ISTANBUL (AP) — Suicide attackers armed with guns and bombs killed 41 people and wounded hundreds at Istanbul’s busy Ataturk Airport, apparently targeting Turkey’s crucial tourism industry. The government blamed the attack on Islamic State extremists but there was no immediate confirmation from the group.

Travelers and airport workers described scenes of chaos Tuesday night as gunfire and explosions sent fleeing crowds first in one direction, then another.

Airport surveillance video posted on social media appeared to show the moment of one explosion, a ball of fire that sent terrified passengers racing for safety. Another appeared to show an attacker, felled by a gunshot from a security officer, blowing himself up seconds later. A growing stream of travelers, some rolling suitcases behind them, fled down a corridor, looking fearfully over their shoulders.

“Four people fell in front of me. They were torn into pieces,” said airport worker Hacer Peksen.

The victims included at least 23 Turkish citizens and 13 foreigners. The death toll excluded the three bombers, who arrived in a taxi and eventually blew themselves up after coming under fire, according to the government, though there were conflicting reports about exactly where they detonated their explosives.

The Istanbul governor’s office said more than 230 people were wounded. Hundreds of passengers who fled the airport in fear were left sitting on the grass outside Tuesday night.

By midday Wednesday, the Islamic State group had not claimed responsibility for the attack, although it did issue an infographic celebrating two years since announcing a caliphate. It claimed to have “covert units” inTurkey, among other places, according to the SITE Intelligence Group.

Funerals for some victims began Wednesday as Turkish authorities tried to piece together how the attack happened, going through surveillance footage and interviewing witnesses to establish a preliminary timeline.

The HaberTurk newspaper reported that one attacker blew himself up outside the terminal, and two others opened fire near the X-ray machines. The report said an attacker was shot at while running amid fleeing passengers, then blew himself up at the exit. It said the third attacker went up one level to the international departures terminal, was shot by police and detonated his explosives.

It was not clear if any attackers were on the loose. Turkish Prime Minister Binali Yildirim said there were no immediate indications of that.

“So, what can we think? We cannot think anything,” said Ali Batur, whose brother died. “A terror attack might happen everywhere, it happens everywhere. … If God permits, we will get over this in unity and solidarity.”

As dawn broke over the destroyed terminal, workers began removing debris from the blast. The airport reopened Wednesday morning, in sharp contrast to the 12-day complete shutdown in Brussels after the deadly airport bombing there. An information board inside showed about one-third of scheduled flights were canceled and a host of others were delayed,

Yildirim said it appeared that the Islamic State group, which has threatened Turkey repeatedly, was responsible.

“Even though the indications suggest Daesh, our investigations are continuing,” Yildirim said, using shorthand for the Islamic State group. He also suggested the attack could be linked to steps Ankara took Monday toward mending strained ties with Israel and Russia.

Turkey has suffered a series of attacks of increasing frequency that have scared away visitors and devastated its economy, which relies heavily on tourism. The country is a key partner in the U.S.-led coalition against the Islamic State group and a NATO member.

Islamic State offered no immediate claim of responsibility, but the extremist group rarely does for attacks inTurkey. One possible reason is a reluctance to be seen as killing fellow Muslims; another is its desire to exploit the violent rift between Turkey and Kurdish rebels, said Anthony Skinner, director of the analyst group Verisk Maplecroft.

“It very clearly meets Islamic State’s strategic objectives to leave this ambiguity,” Skinner said.

Turkey is beset by an array of security threats, including from ultra-left radicals, Kurdish rebels demanding greater autonomy in the restive southeast, and IS militants. It shares long, porous borders with both Syria and Iraq, where IS controls large pockets of territory. Turkish authorities have blamed IS for several major bombings over the past year, including on the capital Ankara, as well as attacks on tourists in Istanbul.

“The reality is that Turkey is situated in a very vulnerable situation geographically speaking,” Skinner said.

Turkish airports have security checks at both the entrance of terminal buildings and then later before entry to departure gates.

The government has stepped up controls at airports and land borders and deported thousands of foreign fighters, but has struggled to tackle the extremist threat while also conducting security operations against Kurdish rebels, who have also been blamed for some recent deadly attacks.

The devastation at Istanbul’s airport echoed the March 22 attack on the Brussels airport, where two suicide bombings ripped through check-in counters, killing 16 people. The Islamic State group claimed responsibility for that attack, as well as an explosion at a Brussels subway station that killed 16 more people.

Belgian Prime Minister Charles Michel said on Twitter: “Our thoughts are with the victims of the attacks at Istanbul’s airport. We condemn these atrocious acts of violence.”

Two South African tourists, Paul and Susie Roos from Cape Town, were due to fly home at the time of the explosions.

“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 handgun.”

Yildirim, the prime minister, called for national unity and “global cooperation” in combatting terrorism.

“This has shown once again that terrorism is a global threat,” Yildirim said. “This is a heinous planned attack that targeted innocent people.”

Dozens of anxious friends and relatives waited early Wednesday outside Istanbul’s Bakirkoy Hospital.

“You can hear that people are wailing here,” said Serdar Tatlisu, a relative of a victim. “We cannot cope anymore, we can’t just stay still. We need some kind of solution for whatever problem there is.”

This year alone, a Jan. 12 attack that Turkish authorities blamed on IS claimed the lives of a dozen German tourists visiting Istanbul’s historic sites. On March 19, a suicide bombing rocked Istanbul’s main pedestrian street, killing five people, including the bomber, whom the authorities identified as a Turkish national linked to IS.

Last October, twin suicide bombings hit a peace rally outside Ankara’s train station, killing 102 people. There was no claim of responsibility but Turkish authorities blamed it on an Islamic State cell.