ISTANBUL: The three suicide attackers who struck Istanbul's main international airport this week are believed to have been planning to take dozens of people hostage, a Turkish newspaper reported Friday.

A total of 44 people were killed in Tuesday night's gun and bomb spree at Turkey's busiest airport, the deadliest in a string of attacks to hit Istanbul this year.

The pro-government Sabah newspaper reported that the attackers scouted the scene and planned to take dozens of passengers hostage inside before carrying out a massacre.

But they began the assault earlier than planned after attracting suspicion, Sabah reported.

“The coats they were wearing to disguise their suicide vests, despite the hot weather, drew the attention of citizens and a police officer,” the paper said.

Turkish authorities believe the Islamic State group was behind the carnage, and have identified the attackers as a Russian, an Uzbek and a Kyrgyz national.

Media have identified Akhmet Chatayev, from Russia's Chechnya region, as the mastermind of the attack, with Hurriyet newspaper claiming he was the head of the IS group's Istanbul cell.

He allegedly organised two deadly bombings this year in the heart of Istanbul's Sultanahmet tourist district and the main Istiklal shopping street earlier this year, Hurriyet reported.

Turkish media showed a CCTV grab purportedly showing the three men wearing dark jackets, two of them in baseball caps.

The Hurriyet newspaper claimed that the bombers had rented a flat in Istanbul's Fatih district, home to many Syrians and other Arabs, and paid 24,000 Turkish lira ($8,300, 7,500 euros) in advance for a year's rent.

The police raided the apartment after the attack, according to an upstairs neighbour, who said the bombers kept the curtains closed.

She never saw the attackers, but she heard them, and complained to local neighbourhood officials about a strange smell.

“A very weird, chemical smell,” she told Hurriyet. “Police came after the bombing ... I lived on top of the bomb.”

Hurriyet also quoted a local plumber, identified only by his initials E.S., who says one of the attackers came to his shop to ask if he could fix their tap.

“He spoke in broken Turkish. He took me home,” the plumber said.

“I changed the tap. I saw three people inside. They looked like bandits. One always stood by me. I left after changing the tap. They paid me 20 Turkish lira.”

Turkish official: Mastermind of Feb 'terror attack' killed

As Turkey pressed ahead with an investigation into the triple suicide bombing at Istanbul's airport bombing and track down suspects, its security forces killed the mastermind of an earlier suicide bombing, an official said Friday.

Mehmet Sirin Kaya was killed in the town of Lice in the mainly Kurdish province of Diyarbakir, the official said. He spoke on condition of anonymity in line with government regulations.

The Feb 17 suicide attack against military personnel in Ankara killed 29 people and was claimed by an offshoot of the Kurdistan Worker's Party, or PKK, which Turkey considers a terrorist organisation.

Authorities said the three suicide bombers in the attack - which echoed the carnage earlier this year at the Brussels airport - were from Russia and the Central Asian nations of Uzbekistan and Kyrgyzstan.

They did not provide further details on their identities.

Thirteen people, suspected of possible links to the attack, were detained in raids in three Istanbul neighborhoods on Thursday, officials said.

Haber Turk newspaper said on its online edition that 11 more suspects - all of them foreign nationals - were detained in a separate raid on a house in Istanbul early on Friday.

A government official in Istanbul could not immediately confirm the report.

The Islamic State militant group has repeatedly threatened Turkey in its propaganda, and the NATO member has blamed it for several major bombings in the past year in both Ankara and Istanbul.

Turkey's interior minister said the explosives used were a mix of RDX, TNT and PETN that were “manufactured”, which chemist and explosives expert at University of Rhode Island, Jimmie Oxley, described as being military-grade, raising the question of how the attackers obtained the bombs.

A key partner in the US-led coalition against the IS, Turkey also faces security threats from the Kurdish rebels who are demanding greater autonomy in Turkey's southeast region and from ultra-left radicals.

Kurdish rebels have carried out numerous car bomb attacks in the past year, including the Feb 17 Ankara attack and another devastating bombing in the capital in March.