Several suicide bombers have hit Istanbul’s Ataturk airport, killing at least 28 people and wounding some 60 others, Istanbul’s governor and other officials said Tuesday.

Turkey’s NTV television quoted Istanbul Governor Vasip Sahin as saying three suicide bombers carried out the attack.

Turkish Justice Minister Bekir Bozdag earlier said that according to preliminary information, “a terrorist at the international terminal entrance first opened fire with a Kalashnikov and then blew himself up.”

Another official said attackers detonated explosives at the entrance of the international terminal after police fired at them.

The official, who spoke on condition of anonymity in line with government protocol, said the attackers blew themselves up before entering the x-ray security check at the airport entrance.

Turkish airports have security checks at both at the entrance of terminal buildings and then later before entry to departure gates. Roads around the airport were sealed off for regular traffic after the attack and several ambulances could be seen driving back and forth.

Hundreds of passengers were spilling out of the airport with their suitcases in hand or stacked onto trolleys. Others were sitting on the grass, their bodies lit by the flashing lights of ambulances and police cars.

Two South African tourists, Paul and Susie Roos from Cape Town, were at the airport and due to fly home at the time of the explosions and were shaken by what they witnessed.

“We came up from the arrivals to the departures, up the escalator when we heard these shots going off,” Paul Roos said. “There was this guy going roaming around, he was dressed in black and he had a hand gun.”

The private DHA news agency said the wounded, among them police officers, were being transferred to Bakirkoy State Hospital.

Turkey has suffered several bombings in recent months linked to Kurdish or Islamic State group militants.

The bombings include two in Istanbul targeting tourists — which the authorities have blamed on the Islamic State group.

The attacks have increased in scale and frequency, scaring off tourists and hurting the economy, which relies heavily on tourism revenues.

Istanbul’s Ataturk Airport was the 11th busiest airport in the world last year, with 61.8 million passengers, according to Airports Council International. It is also one of the fastest-growing airports in the world, seeing 9.2 percent more passengers last year than in 2014.

The largest carrier at the airport is Turkish Airlines, which operates a major hub there. Low-cost Turkish carrier Onur Air is the second-largest airline there.

(AP)