Even as the airport reopened, scenes of grief played out at a nearby hospital. A young woman, wearing a brown and pink head scarf, rocked softly back and forth as an older woman embraced her, sobbing. The young woman’s husband was among the dead.

“My God, why did you take him from me,” she said, her voice breaking.

Those who survived spoke of panic and confusion, and of gunfire aimed directly at them.

A young man said he was going through a metal detector Tuesday night when he heard shooting. He said he came under fire as the assailants advanced, shooting. He saw one person fall to the ground and dove under the X-ray machine.

Adnan Ersoy, a 56-year-old cab driver at the hospital, said that three of his friends, all taxi drivers, had been killed, and that eight were wounded.

“They were just taxi drivers,” he said. “Good people, people who were trying to survive and earn their money.”

Passengers making their way through the first airport security checkpoint on Wednesday seemed shaken.

“It was only God’s grace that separated us from the tragedies that happened here,” said Tanika Golota, 26, a school counselor from Chicago, who was holding her 1-year-old, Mila. The Golotas, on their way home from a vacation in Portugal with a layover in Istanbul, had left the airport just 40 minutes before the explosion Tuesday night.

“You see it on TV and you know it happens, but we are naïve to the fact that it could happen to us,” she said.

A majority of the victims appeared to be Muslims, either Turks or visitors from Muslim countries. If the bombings are confirmed to be the work of the Islamic State, it would show once again that the group, which portrays itself as defending Islam and fighting Western powers, kills far more Muslims on the battlefields of Iraq and Syria or in terrorist attacks in the region, than it does non-Muslims.

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The attack cast a pall over a city that until recently was brimming with self-confidence, projecting itself as a rambunctious, multicultural hub for the arts, with great cuisine and a dazzling history as a former imperial capital.

But a series of terrorist attacks over the last year, some attributed to the Islamic State and others to Kurdish militants, have decimated Turkey’s carefully crafted image as a haven in a dangerous region, and they have damaged its once-thriving tourism industry.

The chaos enveloping Turkey, including the series of attacks and an enormous influx of refugees that has strained resources, vividly illustrates how the civil war in Syria has rippled outward and destabilized neighboring countries.

Turkey is grappling with growing domestic strains as well, with deep divisions between Islamists who support President Recep Tayyip Erdogan and secular and nationalist Turks who oppose what they regard as his increasingly authoritarian grip on power. Making matters worse, a war that Turkey had fought for more than three decades against Kurdish militants resumed last year, turning cities in the southeast into war zones.

Early Wednesday morning, Prime Minister Binali Yildirim said that early indications suggested that the Islamic State, also known as ISIS and ISIL, was behind the latest attack, although officials still had not released any information about the attackers by Wednesday afternoon.

After other attacks, Turkish officials have equivocated, citing as potential culprits either the Islamic State or Kurdish militants. This, critics have said, provided the government with the pretext to crack down further on Kurdish militants, which has been a greater priority for Turkey than fighting the Islamic State.

However, some analysts said the airport attack might be a game-changer for Turkey’s approach to the Islamic State. The United States and other allies have accused Turkey of not doing enough to fight the militant group, and even of contributing to its rise by allowing fighters and weapons to pass through Turkish territory as part of a policy of supporting Syrian rebels.

“I was impressed with the rapidity with which the government said it was Daesh,” said Soli Ozel, a Turkish columnist and professor at Kadir Has University in Istanbul, using the Arabic acronym for the Islamic State. “It suggests to me that finally maybe they have learned what the hell they have done.”

He added, “I think the fight against Daesh will become more serious than it has been.”

The attack came a day after Turkey, which has suffered ruptures in relations with many of its neighbors in recent years, took steps to reconcile with Israel and Russia. Turkey’s relationship with Israel fell apart six years ago after Israel commandos stormed an aid flotilla bound for the Gaza Strip in violation of a blockade, killing several Turkish activists.

In November, Turkey shot down a Russian fighter jet that strayed into its airspace across the Syrian border, raising tensions to a boil. But Mr. Erdogan sent a letter to the Russian president, Vladimir V. Putin, this week expressing remorse for shooting down the jet, and on Wednesday, the two leaders spoke by telephone.

At least part of the reason for patching up relations with Israel and Russia was to help improve Turkey’s beleaguered tourism industry, and it bore quick results: On Wednesday, Russia announced that it would lift a travel ban to Turkey and was moving toward normalizing economic relations.

More than four million Russians went to Turkey in 2014, second only to Germans, but millions of Russian tourists stayed home this year. Moscow also banned most imports of fruits, vegetables and other agricultural goods from Turkey, but that ban is due to be lifted, as well.

Subways and streets in Istanbul were quiet on Wednesday, with tourists who had come despite a string of attacks over the last year — the airport bombings were the fourth suicide attack in Istanbul alone this year — trying to enjoy themselves.

“It’s really sad,” said Alex Afridi, 50, from Sacramento, who was visiting Turkey with his family and staying in a hotel in the Beyoglu neighborhood of Istanbul. “This city was already hurting. It’s an amazing city.”

He had decided to come to Turkey even though relatives kept asking him if it was safe. He said the probability of being killed might be higher in his hometown.

“We have drive-by shootings all the time where we live,” he said.

Turks said they felt stunned at the dismal turn their country had taken.

“I was in a crying mood this morning, looking at the news,” said Osman Serim, 60, a businessman drinking coffee in Beyoglu. “What is going to happen? What is the hope? What is the future for young people?”