TURKEY has detained 68 suspected members of the Islamic State jihadist group including three Russians in raids after a suicide bomb attack in Istanbul.

The arrests were made after an IS suicide bomber killed 10 people in central Istanbul, but the reports did not make clear if there was any connection.

The Russian Consulate in Turkey has confirmed the detentions, according to Russian media.

Sixty-five people were detained in raids in Ankara; Izmir on the Aegean; the Syrian border town of Kilis; Sanliurfa close to Syria; Mersin on the Mediterranean; and the southern city of Adana, the Anatolia news agency said.

In Ankara, the authorities detained 16 people who were suspected of planning a major attack in the capital, the report said.

The 21 people detained in Sanliurfa were also planning an attack at an unspecified location in Turkey, it added.

Today, three more suspected IS members were detained in the southern resort city of Antalya. All three are Russian citizens, it added.

The reports did not make clear if there was any link to the suicide bombing in Sultanahmet Square in central Istanbul, which the authorities said was carried out by an IS jihadist who came from Syria.

Long accused of failing to crack down on IS, Turkey has in recent months moved against cells operating on its territory after several deadly attacks blamed on the group.

SYRIAN BOMBER KILLS TOURISTS

The raids come after a Syrian suicide bomber blew himself up in Istanbul’s busiest tourist district, killing 10 people and injuring at least 15 more.

Grisly images from the scene showed several mutilated corpses close to the iconic Ottoman-era Blue Mosque in Sultanahmet, Turkey’s historic district, after the attack.

“I strongly condemn the terror attack which was carried out by a suicide bomber of Syrian origin,” Turkish President Recep Tayyip Erdogan said. “This incident showed one more time that we should be united against terror.”

Prime Minister Ahmet Davutoglu said the attacker belonged to Islamic State.

“We have determined that the perpetrator of the attack is a foreigner who is a member of Daesh,” Davutoglu said, using an Arabic acronym for ISIS.

Officials earlier said the bomber was a Syrian national born in 1988.

A Turkish official said at least nine of the dead were German, with Davutoglu telephoning Chancellor Angela Merkel to offer his condolences, state media said.

Merkel said the latest attack would deepen German resolve to combat international terrorism.

“Today it hit Istanbul, it has hit Paris, it hit Tunisia, it had already hit Ankara,” she told a news conference in Berlin.

Police and ambulances raced to the scene, throwing up a tight security cordon around the area as helicopters hovered overhead, and crowds of worried locals and tourists clamoured to find out what had happened, an AFP correspondent said.

The explosion took place about 7.20pm AEDT by the Obelisk of Theodosius, an ancient Egyptian monument which was re-erected by the Roman Emperor Theodosius. It stands just outside the Blue Mosque.

The explosion was powerful enough to be heard in adjacent neighbourhoods, witnesses told AFP. Police cordoned off the area to shocked passers-by and tourists and the nearby tram service has been halted.

“The explosion was so loud, the ground shook. there was a very heavy smell that burned my nose,” a German tourist named Caroline told AFP. “I started running away with my daughter. We went into a nearby building and stayed there for half an hour. It was really scary,.”

TURKEY ON HIGH ALERT

Turkey is on alert after 103 people were killed on October 10 when two suicide bombers blew themselves up in a crowd of peace activists in Ankara, the bloodiest attack in the country’s modern history.

That attack was blamed on ISIS jihadists, as were two other deadly bombings in the country’s Kurdish-dominated southeast earlier in the year.

Turkish authorities have in recent weeks detained several suspected ISIS members, with officials saying they were planning attacks in Istanbul.

But Turkey is also waging an all-out assault on the outlawed Kurdistan Workers’ Party (PKK) which has staged dozens of deadly attacks against members of the security forces in the southeast.

The PKK launched an insurgency against the Turkish state in 1984, initially fighting for Kurdish independence although now more for greater autonomy and rights for the country’s largest ethnic minority.

The conflict, which has left tens of thousands of people dead, looked like it could be nearing a resolution until an uneasy truce was shattered in July.

A Kurdish splinter group, the Freedom Falcons of Kurdistan (TAK), claimed a mortar attack on Istanbul’s second international airport on December 23 which killed a female cleaner and damaged several planes.

Meanwhile the banned ultra-left Revolutionary People’s Liberation Party-Front (DHKP-C) has also staged a string of usually small-scale attacks in Istanbul over the last months.