Funerals for victims of the deadly attack at Istanbul's international airport are already being held as investigators pore over security footage of the incident.
Turkey has declared three days of national mourning over the suicide bombings which claimed the lives of 41 people and injured 239 more.
Forty-one people remain in intensive care from the attack which happened on Tuesday night (local time).
Five Saudis and two Iraqis were among the dead, a Turkish official said. Citizens from China, Jordan, Tunisia, Uzbekistan, Iran and Ukraine were also among the 13 foreigners killed.
Among those buried were victims Siddik Turgan and Mustafa Biyikli, who were mourned at funerals in Istanbul on Wednesday.
The Turkish Government, which is blaming the attack on Islamic State (IS) jihadists, has ordered flags be flown at half mast around the country as flights resumed.
As yet, no group has claimed responsibility for the attack.
"It's a jigsaw puzzle … The authorities are going through CCTV footage, witness statements," a Turkish official said.
The attackers had come to the airport by taxi and preliminary findings pointed to IS responsibility.
Two US counter-terrorism officials familiar with the early stages of investigations said IS was at the top of the list of suspects even though there was no evidence yet.
"This attack, targeting innocent people, is a vile, planned terrorist act," Prime Minister Binali Yildirim said.
"There is initial evidence that each of the three suicide bombers blew themselves up after opening fir
One attacker opened fire in the departures hall with an automatic rifle, sending passengers diving for cover and trying to flee, before all three blew themselves up in or around the arrivals hall a floor below, witnesses and officials said.
Video footage showed one of the attackers inside the terminal building being shot, apparently by a police officer, before falling to the ground as people scattered.
The attacker then blew himself up about 20 seconds later.
Turkish President Tayyip Erdogan said the attack should serve as a turning point in the global fight against terrorism, which he said had "no regard for faith or values".
US President Barack Obama and Russian President Vladimir Putin condemned it in separate phone calls with Mr Erdogan, his office said.
Mr Obama joined Turkey in pointing the finger at the IS group for the attacks.
"It's an indication of how little these vicious organisations have to offer beyond killing innocents," Mr Obama said in a seeming reference to IS.
"They're continually losing ground, unable to govern those areas that they have taken over. They're going to be defeated in Syria, they're going to be defeated in Iraq."
White House spokesman Josh Earnest said earlier that Mr Obama had offered Mr Erdogan "any support that the Turks can benefit from as they conduct this investigation and take steps to further strengthen the security situation in their country".
The head of America's Central Intelligence Agency John Brennan also said the attack bore the hallmarks of Islamic State's "depravity".
AFP/Reuters