ISTANBUL: A triple suicide bombing and gun attack at Istanbul's Ataturk airport late Tuesday night killed at least 41 people, including 13 foreigners, and wounded 239 people, the city's governor confirmed as Turkey's prime minister said early signs pointed to an assault by the militant Islamic State (IS) group.

The attackers began spraying bullets at the international terminal entrance before blowing themselves up at around 10:00pm (1900 GMT) Tuesday, Turkish authorities said.

It is the deadliest of four attacks to rock Turkey's biggest city this year, with two others blamed on IS and another claimed by a militant Kurdish group.

Though there was no immediate claim of responsibility for Tuesday's carnage, “the evidence points to Daesh”, Prime Minister Binali Yildirim told journalists at the scene, using another name for the militants. He said the dead included foreigners, but gave no further details.

An Iranian and a Ukrainian have been confirmed as the first foreign victims in the attack, a Turkish official said Wednesday.

“I confirm one Iranian and one Ukrainian national have been killed in yesterday's terror attack,” the official told reporters on condition of anonymity.

The attack prompted the suspension of all flights at the airport — one of Europe's busiest hubs. More than 61 million passengers travelled through the airport in 2015.

Turkish President Recep Tayyip Erdogan called for an international “joint fight” against terror, as Western allies including the United States condemned the “heinous” attack.

Yildirim said the suicide bombers had arrived in a taxi and opened fire on passengers with automatic rifles before blowing themselves up.

Security camera footage widely circulated on social media appeared to capture two of the blasts.

In one clip a huge ball of flame erupts at an entrance to the terminal building, scattering terrified passengers.

Another video shows a black-clad attacker running inside the building before collapsing to the ground apparently felled by a police bullet — and blowing himself up.

Tuesday's attack follows coordinated IS suicide bombings at Brussels airport and a city metro station in March that left 32 people dead.

'The roof came down'

Most of those killed were Turkish nationals but foreigners were also among the dead, a Turkish official said.

Ali Tekin, who was at the arrivals hall waiting for a guest, said the roof came down after an “extremely loud” explosion.

“Inside the airport it is terrible, you can't recognise it, the damage is big,” Tekin said.

A woman named Duygu, who was at passport control after arriving from Germany, said she threw herself to the floor after the explosion.

“Everyone started running away. Everywhere was covered with blood and body parts. I saw bullet holes on the doors,” she said.

Paul Roos, 77, said he saw one of the attackers “randomly shooting” in the departures hall from about 50 metres away.

“He was wearing all black. His face was not masked,” said Roos, a South African on his way home after a holiday in southern Turkey.

"We ducked behind a counter but I stood up and watched him. Two explosions went off shortly after one another. By that time he had stopped shooting,” Roos told Reuters.

“He turned around and started coming towards us. He was holding his gun inside his jacket. He looked around anxiously to see if anyone was going to stop him and then went down the escalator ... We heard some more gunfire and then another explosion, and then it was over.”

'I can't find my sister'

An AFP photographer saw bodies covered with sheets at the terminal, which bore heavy damage from the blasts.

Bullet holes peppered the windows and shattered glass lay on the floor, while abandoned luggage was scattered everywhere.

Hundreds of police and firefighters including forensic officers were at the scene.

“Somebody came and shot at us and then my sister was running,” Otfah Mohamed Abdullah told AFP. “I don't know which way she was running and after that I was falling down. I was on the ground till he finished... I can't find my sister.”

There was panic at the nearest hospital in Istanbul's Bakirkoy district, which was inundated with relatives desperate for news of loved ones.

Security expert Abdullah Agar told CNN Turk the attack bore the hallmarks of IS. “It really bears a resemblance to their methods,” he said in reference to the Brussels bombings, which were claimed by IS.

The US and French consulates warned people to stay away from the area.

Erdogan call

President Tayyip Erdogan said the attack should serve as a turning point in the global fight against militant groups.

“The attack, which took place during the holy month of Ramadan, shows that terrorism strikes with no regard for faith and values,” he said in a statement.

The United States said it stood in solidarity with Turkey, its NATO ally, and that such attacks would only reinforce their joint determination. United Nations Secretary-General Ban Ki-moon stressed the need to intensify global efforts to combat extremism.

Erdogan met with his prime minister and military chief after news of the carnage broke.

“We urge the world, especially Western countries, to take a firm stand against terrorism,” Erdogan said in a statement.

“Despite paying a heavy price, Turkey has the power, determination and capacity to continue the fight against terrorism until the end.”

Istanbul, a major tourism hub that is home to some 15 million people, has suffered a series of attacks in recent months, including a bombing in the heart of the tourist district that killed a dozen German visitors and was blamed on IS.

Two months later, three Israelis and an Iranian were killed in a bombing on the city's main Istiklal shopping street, also blamed on IS.

A blast on the tarmac at Istanbul's other international airport, Sabiha Gokcen, killed a cleaner in December.

Turkey has been hit by at least five attacks blamed on IS militants, including a blast in Ankara in October 2015 that left over 100 dead, though the group has never formally claimed responsibility for an attack in Turkey.

Ankara has meanwhile launched a sustained offensive against the outlawed rebel Kurdistan Workers' Party (PKK) following the collapse of a ceasefire last year.

Hundreds of members of the Turkish security forces have since been killed in PKK attacks.

Flights resume

Ataturk is Turkey's largest airport and a major transport hub for travellers from around the world.

A helicopter buzzed overhead as police evacuated the building.

Dozens of passengers walked back down access roads with their luggage, trying to hail cabs.

Authorities initially halted the takeoff of scheduled flights from the airport and some flights to the airport were diverted.

Yildirim said later air traffic had resumed.

Turkish Airlines said it had suspended its flights until 8:00am (0500 GMT) on Wednesday and that any bookings on flights to or from Ataturk airport could be changed or refunded without cost for the next week.

In the US, the Port Authority of New York and New Jersey reacted to the explosions by putting armed, high-visibility patrols at the three main airports in the New York metropolitan region.

The US Federal Aviation authority also lifted an earlier order grounding US flights to Ataturk.

Pakistan condemns 'mindless' Istanbul attack

Pakistan has strongly condemned the terror attack at Istanbul's Ataturk Airport.

"It is with deep anguish and pain that we have learnt about the terrorist attack at Ataturk airport in Istanbul. We condemn this mindless act of terrorism in the strongest possible terms," Foreign Office spokesperson Nafees Zakaria said in a statement.

Pakistan condemns terrorism in all forms and stands in solidarity with the people of Turkey in their fight against terrorism, he said.

Prime Minister Nawaz sharif while condemning the terror attack offered his condolences to the government and people of Turkey.

The US condemned what it called the “heinous” bombing and gun attack at Istanbul's Ataturk airport and pledged its “steadfast” support for Turkey.

“Ataturk International Airport, like Brussels Airport which was attacked earlier this year, is a symbol of international connections and the ties that bind us together,” White House spokesman Josh Earnest said in a statement.

“We remain steadfast in our support for Turkey, our Nato ally and partner, along with all of our friends and allies around the world, as we continue to confront the threat of terrorism."

UN Chief Ban Ki-Moon also condemned the attack.

“He expresses his deepest sympathy and condolences to the families of the victims and to the Government and people of Turkey. He wishes a speedy recovery to those injured," and hoped that "the perpetrators of this crime will be identified and brought to justice.”

With additional reporting by Mateen Haider in Islamabad.