Turkish police have launched a huge manhunt for the gunman who stormed a nightclub in Istanbul during New Year celebrations and killed 39 people before leaving his weapon behind.

The gunman, who appeared to be dressed in a Santa Claus hat, opened fire in the Reina nightclub in Istanbul's Ortaköy district sending terrified revellers diving into the Bosphorus River for cover.

A further 69 people are thought to have been wounded in the attack, which happened in the early hours of this morning.

Crying relatives gather around the coffin of one of the victims of the Turkish nightclub massacre ahead of a funeral

A young boy breaks down and rests his head on top of the coffin of one of the victims of the massacre

It is unclear who carried out the shooting, however recent terror attacks in Turkey have been carried out by groups such as ISIS and Kurdish militants.

Already people in the city have started burying the dead, just 13 hours after the attack as per Muslim tradition which dictates people should be buried as soon as possible after their death.

And Turkey's Prime Minister Binali Yildirim has revealed that the gunman left his weapon inside the venue and escaped by 'taking advantage of the chaos' that ensued.

But he also said there was no truth to reports that the attacker wore a Santa Claus costume, despite the CCTV footage from inside the club.

A man kisses the top of the coffin of Ayhan Arik, one of the 39 people to be killed in the attack last night

People in the Turkish capital have began burying the dead, just 13 hours after the attack as per Muslim tradition which dictates people should be buried as soon as possible after their death

Fifteen of the casualties are believed to be foreign nationals, including one Israeli woman and people from Saudi Arabia, Morocco, Lebanon and Libya.

The gunman was described as raining down 'a hail of bullets' on the New Year revellers and is still on the run.

And now Turkey's president Tayyip Erdogan has vowed to fight to the end against all forms of attack by terror groups and their backers.

In a statement he said: 'As a nation, we will fight to the end against not just the armed attacks of terror groups and the forces behind them, but also against their economic, political and social attacks.

'They are trying to create chaos, demoralize our people, and destabilize our country with abominable attacks which target civilians.

'We will retain our cool-headedness as a nation, standing more closely together, and we will never give ground to such dirty games.'

CCTV believed to be from inside the club shows a gunman who appears to be wearing a Santa outfit

This morning armed police with shields formed a ring of steel around the nightclub in Istanbul, where 39 people were shot dead

Police secure the area as the convoy of Turkish Interior Minister Suleyman Soylu leaves after his visit to the nightclub where the attack took place

Special forces stand guard outside the nightclub this morning. A further 69 people are thought to have been wounded in the attack

This morning a Turkish police boar was anchored on the Bosphorus close to the nightclub as a manhunt for the killer continues

A Turkish policeman stands guard next to the scene. Turkish interior minister Suleyman Soylu said the attacker has not been identified and is still at large

While the governor of Istanbul Vasip Sahin has described the shooting as a terrorist attack. He revealed that a police officer was among those shot.

He said: 'Unfortunately (he) rained bullets in a very cruel and merciless way on innocent people who were there to celebrate New Year's and have fun.'

Interior minister Suleyman Soylu said the attacker has not been identified and is still at large.

Relatives of the victims gather outside of the forensic medical institute in Istanbul for news about their loved ones

Many of the victims' relatives broke down in tears as they waited on news on their family members

A woman falls to the ground in tears after hearing bad news about one of her loved ones following the nightclub attack

A man and a woman are led away from the institute weeping. The building is where the dead bodies have been taken

Relatives embrace and cry as they wait for news of their family members following the New Year attack

An ambulance brings another body into the Forensic Medical Center in Istanbul following the attack

'Our security forces have started the necessary operations. God willing he will be caught in a short period of time'

'This was a massacre, a truly inhuman savagery' he said.

The British Foreign Office said it is liaising with authorities to establish whether any Britons were caught up in the massacre.

Foreign Secretary Boris Johnson tweeted: 'Thoughts with Turkey after cowardly act of terrorism in Istanbul nightclub attack. We stand shoulder to shoulder with our Turkish friends.'

Footage taken from inside the Reina nightclub around an hour before the attack showed people dancing and ringing in the New Year

The White House condemned the shooting as a 'horrific terrorist attack', and pledged their support to Turkey.

German Chancellor Angela Merkel has sent her condolences to the victims of the Istanbul attack, saying 'terrorists ... have carried out an inhumane and devious attack on people who wanted to celebrate the New Year together.'

'My thoughts this morning are with the victims, their families and friends,' she said.

While Russian president Vladimir Putinhas sent Turkey's president a telegram of condolences, denouncing the Istanbul nightclub attack.

CCTV footage from outside the club showed the gunman walking down the street to the entrance before opening fire at a policeman

A bullet ricochets off a vehicle after the gunman opens fire at the nightclub in Istanbul, where 39 people were killed

It is believed that the policeman the gunman shot dead as he entered the club was Burak Yildiz, pictured

Medics carry a wounded person at the scene after an attack at the popular nightclub in Istanbul

Thirty five people were killed and a further 40 were injured in the atrocity, the city's governor announced

The taxi used by the killer to travel to the Reina nighclub is loaded on to the back of a pick-up truck

Police were seen towing away a taxi from outside the club, which the gunman is believed to have travelled in

'It is hard to imagine a more cynical crime than killing innocent people during New Year celebrations,' Putin said in the message.

'However, terrorists don't share moral values. Our common duty is to combat terrorists' aggression,' Putin added.

Eyewitness Sinem Uyanik said she had to lift bodies off her in order to get out of the building.

It happened at one of the most popular nightclubs in the heart of Istanbul, and footage shows survivors being taken to safety.

The attacker is believed to have shot the law enforcer and a civilian before opening fire inside the nightclub last night.

A Turkish police officer stands on guard at the site of the armed attack which claimed 39 lives

Ambulances outside the scene of the shooting, in which many people are believed to have been injured

The city's governor has said the massacre was a terrorist attack as almost 40 people were gunned down

Turkish special force police officers and ambulances at the site of the armed attack at 1.15am on New Year's Day in Istanbul

It is believed the terrorist set off a smoke bomb during the attack, and was reported to have calmly reloaded his weapon before gunning down more victims.

He did not specify who he believed was behind the massacre.

Turkish authorities have imposed a temporary blackout on coverage of the attack, claiming it may cause 'fear in the public, panic and disorder and which may serve the aims of terrorist organizations'.

US President Barack Obama has offered 'appropriated assistance' to Turkish authorities.

Survivors embrace after the atrocity, which saw a gunman armed with an automatic weapon open fire inside a busy nightclub, killing 39 people

Nightclub owner Mehmet Kocarslan told Turkey's Hurriyet news site that security at the venue had been increased over the past 10 days following warnings from American intelligence officers.

He stated that the attack had been carried out with Kalashikov rifles.

Initial reports suggested that two gunmen had stormed the building, but authorities are currently understood to be searching for one killer.

Turkish news site Virgul reports that the killer was shouting in Arabic during the attack.

The nightclub, which is popular with celebrities, sits on the banks of the Bosphorus

Ambulances were on the scene within minutes of the attack, which claimed 39 lives and left 69 wounded

Eyewitness Sinem Uyanik told the Associated Press she saw several bodies inside the Istanbul nightclub that was attacked during New Year's celebrations.

Her husband Lutfu Uyanik was wounded in the attack.

'Before I could understand what was happening, my husband fell on top me,' she said outside Istanbul's Sisli Hospital.

'I had to lift several bodies from on top of me before I could get out.'

Her husband was not in serious condition despite his wounds.

Armed police on the scene of the atrocity. It is estimated 17,000 police officers were on duty during the New Year's Eve celebrations

Footage from the scene showed at least six ambulances with flashing lights and civilians being escorted out.

Meanwhile, Mehmet Dag, 22, was passing by the club and saw the suspect shoot at a police officer and a bystander.

He said the suspect then targeted security, gunning them down and entering the club.

The eyewitness added: 'Once he went in, we don't know what happened. There were gun sounds, and after two minutes the sound of an explosion.'

Footage filmed by Dag a showed a police officer lying on the ground outside the club, and then a woman.

Dag told the woman, who was lying on the floor face down in a pool of blood, 'my sister, you will get better.' He called for an ambulance.

Meanwhile a handful of WNBA players, including Essence Carson, Chelsea Gray and Jantel Lavender of the Los Angeles Sparks, were next door to the deadly shooting at a nightclub in Istanbul.

A survivor is taken away on a stretcher by ambulance staff after the attack at the nightclub

There is a huge police presence outside the Reina nightclub in Istanbul after gunmen opened fire

It is believed that 17,000 police officers had been on duty in the Turkish city before the attack

Sparks coach Brian Agler confirmed that Carson had texted him that the three players were OK.

She had tweeted earlier in the evening that she was 'stuck inside of the club because of `terror' shooting in Istanbul. Praises to the most high.'

Footage showed ambulances and the lights of an Istanbul bridge when the sound of gunfire rang out inside the club.

The nightclub lies on the European side of the Bosphorus Strait which divides Istanbul in two.

An estimated 17,000 police officers had been on duty in the city. Turkey has been heavily hit by terror attacks in 2016.

The nightclub is one of the city's most popular venues, and past celebrity guests have included Hollywood stars Kevin Costner, Uma Thurman and Salma Hayek, as well as British star Sting.

Yesterday Neslihan Dogruol, a restaurant owner in a chic Istanbul neighborhood, said she hopes for peace in 2017 following a year filled with 'unrest and death.'

'2016 affected everyone badly,' she said, referring to major attacks that hit Turkey in the past year.

The attack happened in one of Istanbul's busiest nightspots as people celebrated New Year's Eve

The Reina nightclub, in Istanbul, where the attack took place. It is a night spot popular with celebrities

The restaurant, adorned with snowflakes and tiny decorative lights for the evening, will have fewer people for dinner, she said.

At a commemoration for the 45 people killed in twin bombings on December 10 in Istanbul, Murat Manoglu hoped for a better year ahead.

'We lived through terrible days,' he said.

Security measures were heightened in major Turkish cities. Traffic leading up to key squares in Istanbul and the capital, Ankara, had been closed.

Armed police on the streets of Istanbul for the New Year's celebrations following the nightclub shooting

TERROR IN TURKEY: ATTACKS IN 2016 On December 19, the Russian ambassador to Turkey Andrey Karlov was shot dead by an assassin as he gave a speech at an art gallery in Ankara. On 10 December 2016, a car bomb exploded near the Besiktas football stadium in the Macka/Dolmabahce area of Istanbul. 44 people, mostly police officers, were killed, and over 150 injured. On 24 November 2016, a bomb exploded near the Governor's office in Adana. 2 people were killed and 21 injured. On 14 October 2016, a rocket attack took place on the outskirts of Antalya towards Kemer; no casualties were reported. Separately on 14 October 2016, attacks also took place against the Turkish military in Hakkari, Diyarbakir, Van and Adiyaman resulting in 13 injuries to service personnel On 6 October 2016, an explosion occurred near a police headquarters in the Yenibosna area on the European side of Istanbul On 24 August 2016, a roadside bomb injured 2 Gendarmerie officers on the Antalya – Kemer road near Topcam. On 20 August 2016, an attack on a wedding party in Gaziantep killed more than 50 people and injured around 100. On 28 June 2016, Ataturk International Airport in Istanbul was attacked. More than 40 people were killed. On 7 June 2016, a bomb attack in the Vezneciler area of Istanbul killed 7 police officers and 4 civilians. 36 people were injured. On 1 May 2016, a bomb attack at the Central Police Station in Gaziantep killed two police officers and injured 23 others. On 27 April 2016, there was a suspected suicide bomb attack at Bursa Ulu Mosque. The bomber was killed and 7 people slightly injured. On 19 March 2016, there was a suicide bomb attack against tourists on Istiklal St in Istanbul, in which 4 tourists died and at least 36 people were injured. On 13 March 2016, a bombing in Kizilay Square, central Ankara killed more than 30 people. On 17 February 2016, a large bomb attack near a military barracks on Eskisehir Road in Ankara killed 28 people. On 12 January 2016, a suicide bomb attack in Sultanahmet in Istanbul killed 10 tourists. (Source: gov.uk) Advertisement

European cities on high alert as revellers welcome in 2017

The attack in Istanbul came as police in cities across Europe were on high alert over fears of a New Year terror attack.

In London, where 2017 was welcomed in with a huge fireworks display around the London Eye, more offficers than ever before had lined the streets.

More than 3,000 officers patrolled the British capital with guns and sniffer dogs and for the first time ever, armed police were on the London Underground network.

On guard: Two officers stand at the ready in central London where more than 110,000 people gathered for New Year celebrations

Police officers gathered for a meeting as they prepared to patrol the streets while hundreds gathered to watch the fireworks

A steel wall was also erected on London's Westminster Bridge to prevent a lorry attack

In Berlin, which is sitll mourning the truck terror attack that killed 12 people earlier this month, revellers around the Brandenburg Gate were guarded by hundreds of armed police.

In addition concrete blocks and heavy armoured vehicles were put in place along thoroughfares.

On guard: Citizens of Berlin, still mourning the truck terror attack that killed 12 earlier this month, were guarded by hundreds of armed police who placed concrete blocks and heavy armoured vehicles along thoroughfares near the Brandenburg Gate

Cologne: Police officers in the German city stand guard in front of Hauptbahnhof main railway station

Paris: France's President Francois Hollande reviews police officers as he visits the security measures at the Champs Elysees before ushering in 2017

Elswehere in Cologne, where 600 women were sexually assaulted amid last year's festivities, around 1,800 officers were deployed compared to just 140 in 2015.

And in Paris yesterday, French President Francois Hollande met with beefed up security forces who were guarding celebrations around the Eiffel Tower.

In Brussels, which also experienced a terror attack last year, and in Madrid, party-goers were searched by armed police, who kept a careful eye on the swelling crowds.

Brussels: Revellers queue to get in the De Brouckere square for the fireworks performance as Belgium's police officers conduct searches