Three suicide attackers killed 41 people, including 13 foreigners, at Istanbul's main international airport, Turkish officials said Wednesday, with Islamic State the prime suspect in the carnage and panic at the global transit hub.
Among the dead were 23 Turks, while 239 people were injured in the attack, Istanbul Governor Vasip Sahin said.
The foreign nationals include: five from Saudi Arabia; two Iraqis; and one each from Palestine, Tunisia, Uzbekistan, China, Iran, Ukraine and Jordan.
The airport, one of the largest in the region, was shut for several hours after the brutal attack, which left many people stranded. Planes began landing just before dawn, and the first departures took off in the morning, as the airport partially resumed operations.
Delays remained widespread after hundreds of flights were cancelled or postponed immediately after the attack, which involved guns and explosives.
The building's exterior and interior had suffered some damage in the multiple explosions and gunfights between police and the assailants, who have not been included in the official death toll and whose nationality has not yet been confirmed. No group claimed the attack.
Witnesses and local media said there was chaos and panic in the moments during and after the attack, adding there were explosions and gunfire at different points in the terminal, including inside the building. The attack seemed focused on the arrivals area.
Turkish airlines, which had to cancel more than 340 flights, was offering refunds or alternative tickets, but there still was chaos for many travellers, including people who fled the airport attack, their suitcases in hand.
The attack comes as Turkey's key tourism sector has already been battered in recent months due to terrorist attacks and a diplomatic row with Russia. The number of foreign visitors decreased by 35 per cent in May, the latest in a string of steep monthly declines.
Three suicide bombers, who arrived by a regular yellow taxi, struck on Tuesday around 9:20 pm (1820 GMT), officials said. The taxi driver was questioned by the authorities and later released. There has been no confirmation of any arrests following the attack.
Islamic State was the primary suspect, said Prime Minister Binali Yildirim while visiting the airport overnight and announcing it was reopening, just hours after the violence unfolded.
Turkish President Recep Tayyip Erdogan condemned the "terrorist attack" on "innocent civilians."
Speaking after a phone call with Erdogan, US President Barack Obama vowed to support Turkey and dismantle the "networks of hate that have had an impact on the entire civilized world."
The US State Department had issued a warning of "increased threats" in fellow NATO member Turkey on Monday. US aviation authorities grounded all flights to and from Istanbul after the attack though airport data showed some flights from North America had resumed.
One of the attackers detonated explosives inside the terminal by a security check, while another blew himself up outside the terminal and the third in a parking area, Turkish officials said.
Ataturk has security checks with X-ray machines and metal detectors both at the entrance to the terminal, before the check-in counters, and again by passport control.
Tuesday's attack was the worst in Istanbul in more than a decade. Islamic State, which controls territory in neighbouring Syria, was blamed for a number of attacks in Turkey over the past year.
Turkey was accused for years of having a porous border with Syria, which was utilized by extremists joining hardline Islamic factions in the war-torn neighbour.
Three weeks ago, 11 people were killed in an attack near Istanbul's historic Grand Bazaar, claimed by a Kurdish splinter group. A ceasefire between the state and Kurdish militants in the south-east fell apart last year after peace talks stalled.
There were two other attacks in the city this year, both blamed on Islamic State, plus car bombings in the capital Ankara.
In December, Sabiha Gokcen airport in Istanbul was hit by mortar fire claimed by the Kurdistan Freedom Falcons (TAK), killing at least one staff member.