Shooting broke out between security forces and a group of men in eastern Sri Lanka during a search operation related to the Easter Sunday attacks, said the military.

Brigadier Sumith Atapattu said the gun battle began after soldiers were fired upon when they investigated an explosion in the coastal town of Sammanthurai​, 320 km (200 miles) from the capital.

According to Sri Lankan media reports, the security forces raided a property believed to have been used to manufacture suicide vests.

Police spokesman Ruwan Gunasekara said officers in Sammanthurai had found explosive materials, including 150 sticks of blasting gelatin and 100,000 small metal balls, as well as a van and clothing suspected to be used by those involved in the Easter bombings.

Suicide bomb vests have previously been packed with metal balls to increase the shrapnel in the explosion.

Sri Lanka: Scene of the bomb attacks and aftermath Show all 38 1 /38 Sri Lanka: Scene of the bomb attacks and aftermath Sri Lanka: Scene of the bomb attacks and aftermath Sri Lankan Special Task Force officers raid a house following an explosion in capital Colombo AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath A blood-spattered statue of Jesus Christ while crime scene officials inspect the site of a bomb blast, as the sun shines through the blown-out roof, inside St Sebastian's Church in Negombo Reuters Sri Lanka: Scene of the bomb attacks and aftermath A police officer inspects the damage after a bombing at the Shangri-La Hotel in Sri Lankan capital Colombo AP Sri Lanka: Scene of the bomb attacks and aftermath Sri Lankan soldiers look on inside the St Sebastian's Church at Katuwapitiya in Negombo following a bomb blast during the Easter service AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath A woman cries next to a coffin of a bomb blast victim. A series of eight devastating bomb blasts ripped through high-end hotels and churches holding Easter services in Sri Lanka on April 21, killing more than 300 people AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath People who live near the church that was attacked the day before, leave their houses as the military try to defuse a suspected van before it exploded in Colombo Reuters Sri Lanka: Scene of the bomb attacks and aftermath Shoes and belongings of victims are collected as evidence at St Sebastian's Church AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath Sri Lankan police were forded to clear an area while Special Task Force Bomb Squad officers inspected the site of an exploded van near a church the day after it was attacked Reuters Sri Lanka: Scene of the bomb attacks and aftermath The Kingsbury Hotel in Colombo, Sri Lanka following a bombing AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath Queues at the National Blood Bank in Colombo, Sri Lanka after a request for blood to aid in recovery efforts Mr Lavasquabble/Twitter Sri Lanka: Scene of the bomb attacks and aftermath Medical response team work to remove dead bodies from the scene of bombings in Sri Lankan capital Colombo AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath Sri Lankan security personnel inspect the debris of a car after it exploded when police tried to defuse a bomb AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath Security personnel work at the scene of a bombing at a church in Batticaloa in Sri Lanka AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath A woman is helped near St Anthony's Shrine after a blast in Colombo, Sri Lanka, on Sunday 21 April 2019. At least 130 people were killed and more than 500 hospitalised after near-simultaneous explosions hit three hotels and three churches on Easter Sunday. AP Sri Lanka: Scene of the bomb attacks and aftermath Sri Lankan police officers clear the road as an ambulance drives through carrying injured of church blasts in Colombo, Sri Lanka, on Sunday 21 April 2019 AP Sri Lanka: Scene of the bomb attacks and aftermath A Sri Lankan soldier stands guard near a car explosion AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath A woman prays at St. Sebastian's Church in Negombo AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath Priests stand inside St Anthony's Shrine, Kochchikade church on the outskirts of Colombo after a bombing Reuters Sri Lanka: Scene of the bomb attacks and aftermath A Sri Lankan woman living near St. Anthony's shrine runs for safety with her infant after police found explosive devices in a parked vehicle in Colombo AP Sri Lanka: Scene of the bomb attacks and aftermath People react during a mass for victims, two days after a string of suicide bomb attacks on churches and luxury hotels Reuters Sri Lanka: Scene of the bomb attacks and aftermath Security personal react as a device was detonated in a controled explosion in a van near the St Anthony's Church EPA Sri Lanka: Scene of the bomb attacks and aftermath Security forces inspect the scene of a bombing at the Shangri-La Hotel in Sri Lankan capital Colombo Getty Sri Lanka: Scene of the bomb attacks and aftermath The Kingsbury hotel in Colombo, Sri Lanka after a bombing attack Getty Sri Lanka: Scene of the bomb attacks and aftermath The damaged interior of a church in Negombo, Sri Lanka following a bombing attack Reuters Sri Lanka: Scene of the bomb attacks and aftermath Police and security personnel stand guard outside the Shangri-La Hotel in Sri Lankan capital Colombo following a bombing attack EPA Sri Lanka: Scene of the bomb attacks and aftermath Debris is seen at St Anthony's Church in this still image from video footage after explosions hit churches and hotels in Colombo, Sri Lanka, on 21 April 2019 Derana TV/via Reuters Sri Lanka: Scene of the bomb attacks and aftermath Damage inside a church following a bombing attack AP Sri Lanka: Scene of the bomb attacks and aftermath A Sri Lankan Special Task Force officer scales a house during a raid following an explosion in capital Colombo AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath A general interior view showing damage after an explosion hit St Anthony's Church in Kochchikade, Colombo, Sri Lanka, on Sunday 21 April 2019 EPA Sri Lanka: Scene of the bomb attacks and aftermath Priests walk into St Anthony's Shrine Kochchikade church after an explosion in Colombo, Sri Lanka, on 21 April 2019 Reuters Sri Lanka: Scene of the bomb attacks and aftermath A Sri Lankan police officer stands outside St Anthony's Shrine in Colombo, Sri Lanka, after a blast on Sunday 21 April 2019 AP Sri Lanka: Scene of the bomb attacks and aftermath A shoe of a victim is seen in front of the St Anthony's Shrine, Kochchikade Church Reuters Sri Lanka: Scene of the bomb attacks and aftermath Local and security officials gather at the scene at St Anthony's Church in Kochchikade, Colombo, Sri Lanka EPA Sri Lanka: Scene of the bomb attacks and aftermath An ambulance is seen outside the church premises with gathered security personnel following a blast at St Anthony's Shrine in Kochchikade, Colombo, on Sunday 21 April 2019 AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath Armed policemen patrol the area after an explosion hit at St Anthony's Church in Kochchikade in Colombo, Sri Lanka, 21 April 2019 EPA Sri Lanka: Scene of the bomb attacks and aftermath Sri Lankan Army soldiers secure the area around St. Anthony's Shrine after a blast in Colombo, Sri Lanka, Sunday 21 April 2019 AP Sri Lanka: Scene of the bomb attacks and aftermath Sri Lankan security personnel keep watch outside the church premises following a blast at the St Anthony's Shrine in Kochchikade, Colombo, on Sunday 21 April 2019 AFP/Getty Sri Lanka: Scene of the bomb attacks and aftermath Police officers inspect the scene after an explosion hit at St Anthony's Church in Kochchikade in Colombo, Sri Lanka, 21 April 2019 EPA

Police also announced a 24-hour curfew until further notice in the Muslim-dominated area where Friday’s shooting took place.

Since the suicide bombings on churches and hotels in which more than 250 people were killed, police and military personnel have been conducting raids across the country.

The authorities are trying to track down 140 people believed linked to Isis, which claimed responsibility for the bombings. Police have detained at least 76 people, including foreigners from Syria and Egypt, in their investigations so far.

Isis provided no evidence to back its claim that it was behind the attacks. If true, it would be one of the worst attacks carried out by the group outside Iraq and Syria. The extremist group released a video on Tuesday showing eight men standing under a black Isis flag and declaring their loyalty to its leader, Abu Bakr Al-Baghdadi.

Sri Lankan security personnel guard house of one of the suspected suicide bombers in Colombo, April 23 (AFP)

The government said nine homegrown, well-educated suicide bombers carried out the attacks, eight of whom had been identified. One was a woman.

Authorities have so far focused their investigations on international links to two domestic Islamist groups – National Thawheed Jama’ut and Jammiyathul Millathu Ibrahim – they believe carried out the attacks.

Government officials have acknowledged a major lapse in not widely sharing an intelligence warning from India before the attacks.

President Maithripala Sirisena said top defence and police chiefs had not shared information with him. “The police chief said he will resign now,” Mr Sirisena said.

He blamed Prime Minister Ranil Wickremesinghe’s government for weakening the intelligence system by focusing on the prosecution of military officers over alleged war crimes during a decade-long civil war with Tamil separatists that ended in 2009.

A security officer stands guard outside St Anthony’s Shrine (Reuters)

Mr Sirisena fired Mr Wickremesinghe in October over political differences, only to reinstate him weeks later under pressure from the Supreme Court.

Opposing factions aligned to Mr Wickremesinghe and Mr Sirisena have often refused to communicate with each other and blame any setbacks on their opponents, government sources say.

Sri Lanka’s former wartime defence chief, Gotabaya Rajapaksa, said on Friday he would run for president in elections this year and would stop the spread of Islamist extremism by rebuilding the intelligence service.

Gotabaya, as he is popularly known, is the younger brother of former president Mahinda Rajapaksa and the two led the country to a crushing defeat of separatist Tamil rebels a decade ago after a 26-year civil war.

Sri Lanka bombings: CCTV shows suspect moments before church blast

Muslims in Sri Lanka were urged to pray at home and not after the State Intelligence Services warned of possible car bomb attacks, amid fears of retaliatory violence.

There will be no Sunday Masses until further notice after the Easter bombings in Sri Lanka, the Archbishop of Colombo has said.

The US Embassy in Sri Lanka also urged its citizens to avoid places of worship over the weekend after authorities reported there could be more attacks targeting religious centres.

Muslim worshippers attend Friday prayers at Dawatagaha Jumma Masjid in Colombo, Sri Lanka (Getty Images)

Meanwhile, Kingston University in southwest London has confirmed a student with the same name as one of the suspected Sri Lanka bombers attended the establishment during 2006 and 2007.

Abdul Lathief Jameel Mohamed – previously named in media reports – is said to have studied aerospace engineering at the university.

British security officials confirmed that they are investigating Mohamed’s stay in this country. A spokeswoman for the university confirmed on Friday he is listed on records as Jameel Mohamed Abdul Lathief.

“The university does not tolerate any form of incitement to hatred or violence, and condemns in the strongest terms extremist activity,” she said.