The first departures took off from Istanbul's Ataturk international airport Wednesday, as the major global transit hub partially resumed operations following a brutal attack killing 36 people and causing carnage, with Islamic State the top suspect.

Planes had already begun landing just before dawn, after the airport - one of the largest in the region - had been totally shut for several hours following the triple suicide bombing the previous evening which was focused on the arrivals terminal.

Foreign nationals were among the killed and injured, with Turkish citizens making up the largest portion of the victims, officials said, confirming an Iranian and a Ukrainian were killed.

Delays remained widespread after hundreds of flights were cancelled or postponed immediately after the attack, which involved guns and explosives and caused damage to the airport. Witnesses said there was chaos and panic in the moments during and after the attack.

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.

The attack comes as Turkey's key tourism sector is already being 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.

The building's exterior and interior had suffered some damage in the multiple explosions and gunfights between police and the assailants, whose nationality has not yet been confirmed. No group has claimed the attack.

Three suicide bombers who arrived by taxi struck on Tuesday around 9:20 pm (1820 GMT), killing 36 people besides themselves and leaving an estimated 147 injured, officials said.

Witnesses and local media reports said there were explosions and gunfire at different points in the international area of the airport, including inside the building.

Islamic State was the primary suspect, said Prime Minister Binali Yildirim, who visited the airport overnight and announced it open to inbound and outbound flights.

Turkish President Recep Tayyip Erdogan condemned the "terrorist attack" on "innocent civilians."

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 has been blamed for a number of attacks in Turkey over the past year.

Three weeks ago, 11 people were killed in an attack near Istanbul's historic Grand Bazaar, claimed by a Kurdish splinter group. 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.

Latest news

Syrian opposition rules out future role for President al-Assad

The Syrian opposition said Friday it would not accept any role for President Bashar al-Assad in the future of the war-torn country, reacting to a recent US shift saying that removing al-Assad is no longer a priority for Washington.

Russian Army integrates breakaway forces of Georgian province

Parts of the small fighting forces of the Georgian breakaway province of South Ossetia have been placed under Russian military control, Russian Defence Minister Sergei Shoigu said on Friday.

Czech Republic's Pilsner Urquell beer is now Japanese

Japanese brewing company Asahi completed its takeover of the Czech brewery Pilsner Urquell on Friday, Asahi said in a statement.

Judge approves 25-million-dollar settlement of Trump University case

A US district judge on Friday approved a 25-million-dollar settlement of lawsuits and state fraud allegations against Trump University, the US president's now-defunct business venture.

Former Thai premier Thaksin to junta on reconciliation: 'Cut me out'

Former Thai prime minister Thaksin Shinawatra on Friday announced that he is not interested in the junta-led reconciliation process, three days after the junta handed him a half-a-billion-dollar tax bill for his past business deal.

Dalic: We welcome possible deal between Agrokor and banks

The government welcomes the possibility of an agreement being concluded between the Agrokor food company and creditor banks, and the bill on vitally important companies is not a fallback plan but the result of the government's care for the overall economic and financial stability of Croatia, Deputy Prime Minister and Minister of Economy Martina Dalic told a press conference in Zagreb on Friday.

Croatia, China sign action plan for cooperation in agriculture

The Croatian and Chinese ministries of agriculture on Friday signed an action plan for cooperation in the field of agriculture for the period 2017-2018, the Croatian ministry said in a statement.

ZSE indices up, Agrokor shares in focus of investor interest

The Zagreb Stock Exchange (ZSE) indices on Friday rose by more than 1.8%, with stocks of the Agrokor food and retail concern being in the focus of investor interest again.

Berlin police defend handling of Berlin market attacker

Berlin police defended themselves on Friday against accusations that they stopped surveillance on Berlin Christmas market attacker despite knowing in June 2016 he was dangerous.

Croatia, creditors tailor emergency measures to save tottering giant

Croatia's tottering retail and food giant Agrokor reached an agreement with its creditors, putting its debts standby and allowing it to continue working during emergency restructuring, the Croatian branch of Austria's Erste Bank said Friday.

Agrokor's creditors say standstill agreement to go into force today

A standstill agreement regarding the Agrokor concern's existing financial obligations to banks will take effect on Friday, additional capital will be injected into the concern in the coming days and the concern will be actively restructured, which includes a change of its management, it was said on Friday after a meeting between Agrokor's suppliers and creditor banks.

Palestinians, UN slam Israel's new settlement plan

Palestinians, Israeli activists and the UN lambasted the government of Israeli Prime Minister Benjamin Netanyahu on Friday, a day after it gave the go-ahead for the first new West Bank settlement in a quarter of a century.

South Sudan rebels release three abducted foreign oil workers

South Sudanese rebels have released three foreign engineers they abducted in early March in the oil-rich Upper Nile region, Foreign Affairs Ministry official Mawein Makol Arik said on Friday.

Turkish opposition: Imprisoned party chief has gone on hunger strike

The head of Turkey's pro-Kurdish opposition party has launched a hunger strike from prison.

European leagues threaten Champions League schedule clashes

The European Professional Football Leagues (EPFL) on Friday threatened schedule clashes on Champions League matchdays in an ongoing dispute with the governing body UEFA.

Danish court revokes citizenship of IS volunteer

A Danish appellate court on Friday stripped a man of his Danish citizenship for volunteering to fight for the extremist Islamic State in Syria.

Banks and Agrokor agree on key elements of standstill agreement

Member banks of the coordinating committee of financial creditors and representatives of the Agrokor food company have in principle agreed on key elements of a standstill agreement, which is expected to be signed later today, announcing changes in the company's management team, Erste Bank said in a statement on Friday afternoon.

Syrian man on trial in Sweden; mosque attack labelled terrorism

A Syrian man went on trial Friday in the southern Swedish city of Malmo, charged with terrorism and arson after an attack last year on a building used as an assembly hall by Shiite Muslims.