The death toll in a gun and suicide bomb attack on Istanbul's Ataturk airport has risen to 41, 13 of them foreign nationals, with 239 injured, the Turkish city's governor says.

Three attackers arrived in a taxi and began firing at the terminal entrance late on Tuesday. They blew themselves up after police fired back.

PM Binali Yildirim said early signs pointed to so-called Islamic State.

However, no-one has so far admitted carrying out the attack.

Turkey has declared Wednesday a day of national mourning.

Turkish investigators are examining CCTV footage, witness statements and mobile phone video recorded by terrified passengers to try to determine the identity of the attackers.

The Dogan news agency said autopsies on the three dead men suggested they may be foreign nationals but this has not been confirmed.

A worker cleans blood from the roof of the international departure terminal 

Istanbul's governor confirmed that at least 13 of the 41 dead were of foreign or dual nationality.

Some 109 of those injured have now been discharged from hospital.

UK Prime Minister David Cameron said there were no reports yet of any British casualties, but the Foreign Office was in contact with Turkish authorities.

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Nationality of dead so far confirmed (may include dual nationality)

23 - Turkish

5 - Saudi

2 - Iraqi

1 - Chinese; Jordanian; Tunisian; Uzbek; Iranian; Ukrainian; (Palestinian ambassador to Turkey says one Palestinian woman killed)

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Cleaners worked through the morning to sweep up shattered glass, while workers repaired cables and ceiling tiles. Heavily-armed security personnel were patrolling the airport.

Flights had resumed in the early morning, though with many cancellations and delays.

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