Turkey is observing a national day of mourning after a terror attack on Istanbul’s Ataturk airport killed 41 people, including 13 foreign nationals.

Officials say three attackers began shooting outside and inside the terminal late on Tuesday and blew themselves up after police fired at them. So far 23 Turks and at least 13 other foreign nationals have been identified among the dead.

Prime Minister Binali Yildirim said early signs suggested the so-called Islamic State was behind the attack.

Recent bombings have been linked to either IS or Kurdish separatists.

Ataturk airport has long been seen as a vulnerable target.

There are X-ray scanners at the entrance to the terminal but security checks for cars are limited.

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

“The bombs that exploded in Istanbul today could have gone off at any airport in any city around the world,” he said.

The US called the attack “heinous”, saying America remained “steadfast in our support for Turkey”.

German Foreign Minister Frank-Walter Steinmeier said: “We grieve for the victims. We stand by Turkey”.

Speaking several hours after Tuesday’s attack, PM Yildirim said at least 36 people were killed and many wounded, some seriously, with foreigners likely to be among the victims.

Justice Minister Bekir Bozdag put the number of injured at 147.

Desperate relatives of those missing later gathered outside a local hospital where many victims were taken. Some expressed anger about the lack of information.

Flights in and out of the airport were suspended after the attack.

Flights have now resumed at the airport, but information boards showed about one-third had been cancelled, with many delays.