ISTANBUL -- [Latest developments, published at 8:40 p.m. ET]
--At least 36 people were killed in the terror attack at Istanbul Ataturk Airport, Turkish Prime Minister Binali Yildirim said. "The signs point to Daesh but the investigation is ongoing," he said. Daesh is another name for ISIS.
--Another 147 people were wounded, Turkey's Justice Minister Bekir Bozdag said. Three bombers were also killed, Istanbul Gov. Vasip Sahin said. A total of 49 ambulances were sent to the site.
--Speaking on national television, Yildirim said the attackers arrived at the airport by taxi. "The fact that they were carrying guns added to the toll. Preliminary findings suggest all three attackers first opened fire then detonated themselves," he said
-- There has been no immediate claim of responsibility.
--U.S. officials said the attack bears the hallmarks of ISIS because of the target and method. There's a good possibility a Turkish cell was responsible for the attack, a U.S. official said, pointing to Brussels and Paris as examples of ISIS terrorists launching attacks on home turf they're familiar with.
--Turkish President Recep Tayyip Erdogan called for a unified international fight against terrorism, saying: "Make no mistake: For terrorist organizations, there is no difference between Istanbul and London, Ankara and Berlin, Izmir and Chicago or Antalya and Rome. Unless all government and the entire mankind join forces in the fight against terrorism, much worse things than what we fear to imagine today will come true."
-- CNN journalist Joe Duran said from the airport that "Police are not letting anyone in ... Hundreds of people are flooding away from airport... People are trying to get away. They're not saying much -- just the look on their face is enough, shock, some of them bleeding..."
"People are walking away bleeding, with bandages on their head."
-- Traveler Laurence Cameron described what he saw after he stepped off a plane: "It was just a massive crowd of screaming people. Some were falling over themselves. A poor chap in a wheelchair was just left, and everyone just rushed to the back of the building, and then people ran the other way and no one really seemed to know what was going on," he told CNN. "Where you normally hail a taxi, that is where the attack happened. The ground is just kind of shredded. There is bloodstains on the floor as well."
-- Bozdag earlier said one terrorist "first opened fire with a Kalashnikov then detonated himself."
-- In total three bombs exploded, the governor said.
-- A video posted to Twitter shows a view from a camera inside an airport terminal. A few dozen people are walking around when a bright flash and fireball erupt in the background.
--Another video shows a man falling to the floor in the terminal, apparently after being shot by a law enforcement officer. The man drops his assault rifle, which skitters across the floor. The officer appears to shoot a second time and runs. A flash covers the video, apparently caused by the fallen man detonating a bomb.
--Sue Savage told CNN she was inside the airport seeing a friend off when she heard gunshots and then an explosion, which she knew was a bomb. She hid in a men's prayer room and then a men's toilet, a room where luggage is inspected and finally a women's prayer room. Security led a group of about 30 people out of that room and down an escalator into the main terminal hall.
"There was a LOT of blood," she said. The floor was marked with bloody boot marks and she saw a woman's scarf on the floor. The group was herded around to the other side of the room.
"There was so much glass on the floor they were scuffing it aside so we didn't slip," she said.
-- A Turkish official told CNN that police fired shots at suspects near the international terminal in an effort to neutralize them.
-- Videos posted on social media show travelers sitting on the airport floor. A man shouts, "Get down! Get down!" Someone cries as a gunshot rings out.
--There are no known American casualties yet, said U.S. Rep. Eric Swalwell, (D-California), a member of the House Intelligence Committee.
--The attack is another blow to the Turkish tourism business, the second biggest part of the nation's economy.
-- Erdogan met with Yildirim and the Chair of the Joint Chiefs, General Hulusi Akar, at the presidential palace upon receiving news of the explosions in Istanbul, the office of the president announced.
The President's office says that the prime minister, Deputy PM Numan Kurtulmus, Transportation Minister Ahmet Arslan and Family and Social Policies Minister Fatma Betul Sayan will travel to Istanbul from Ankara, the Turkish capital.
-- U.S. Secretary of State John Kerry, referencing the attack in Istanbul, told an audience at the Aspen Ideas Festival on Tuesday, "We are still collecting information and trying to ascertain what happened and who did it."
-- Ataturk Airport is "one of the most secure airports in the world," CNN senior law enforcement analyst Tom Fuentes says. But the airport has been "very overwhelmed for several decades with terrorism from PKK."
-- The U.S. Federal Aviation Administration has put in place a ground stop for any U.S. flights that were scheduled to fly to Istanbul and any flights leaving Istanbul for the United States, CNN's Rene Marsh reports.
-- The Ataturk airport is closed until Wednesday at 5 a.m. local time (10 p.m. ET), according to the airport's Twitter account. Airport spokesman Erhan Ustundag said that the rest of Tuesday's incoming flights were diverted to Izmir, Ankara and other cities.
-- The U.S. embassy in Ankara is sending consular officers to the airport to account for any potential U.S. victims. But there are no indications of any American casualties at this point, a senior State Department official told CNN's Elise Labott.
-- The White House issued a statement: "Ataturk International Airport, like Brussels Airport which was attacked earlier this year, is a symbol of international connections and the ties that bind us together. Our deepest condolences go out to the families and loved ones of those killed, and we wish a speedy recovery to those injured. We remain steadfast in our support for Turkey, our NATO ally and partner, along with all of our friends and allies around the world, as we continue to confront the threat of terrorism."
-- The attacks happened on a warm summer night at the airport, east of Istanbul, that is the 11th busiest in the world in terms of passenger traffic. CNN's Ali Veshi says it is a modern, sophisticated airport. "There are all of the major European and American boutiques there," said Velshi, who has traveled through Turkey many times. "... You see people of all shapes and colors, in all sorts of dress. If you want to target the cosmopolitan nature of Istanbul, this is possibly the most cosmopolitan, heavily populated part. You can target tourist areas, but this is the part where the world comes together."
[Original story, published at 4:02 p.m. ET]
Two explosions and gunfire rocked Istanbul Ataturk Airport Tuesday, Turkey's semi-official news agency Anadolu reported.
The report referenced multiple injuries, but the exact number was not immediately clear.
The report says the explosions occurred in the international departures area of the airport.
Video on Turkish television showed a string of ambulances and fire trucks at the scene as authorities scurried under crime-scene tape.
Turkey has been rocked by a string of terror attacks over the past year as it weathers bombing campaigns carried out both by ISIS and Kurdish militants.
As part of the U.S.-led coalition against ISIS, Turkey allows coalition planes to fly raids on ISIS targets in neighboring Iraq and Syria from its territory.
And last year Turkey resumed hostilities with the PKK, Kurdish militant separatists, in earnest after a two-year cease fire broke down.
The PKK, or Kurdistan Worker's Party, has been in an armed struggle with the Turkish government for decades and is considered a terror group by Turkey, the United States and the European Union.
In March, at least 37 were killed when a car bomb detonated near a bus stop in the Turkish capital, Ankara, in an attack claimed by a Kurdish militant group.
Six days later an ISIS suicide bomber detonated himself on one of Istanbul's main streets, killing four.
A month earlier, 28 were killed in a blast targeting military vehicles in central Ankara. A Kurdish group claimed responsibility.
And in January, at least 10 German tourists died in a suicide bombing in Istanbul's Sultanahmet Square that Turkish authorities linked to ISIS.
The violence has had an impact on Turkey's tourism industry, a key sector of the national economy.