ISTANBUL — A Syrian suicide bomber set off an explosion in the historic central district of Istanbul on Tuesday, killing 10 people and wounding at least 15 others, in an attack that the Turkish government attributed to the Islamic State.

All of the dead were foreign citizens, including Germans and a Peruvian. The wounded included nine Germans, along with citizens of Norway, Peru, South Korea, and Turkey. The government said that a Syrian man born in 1988, who entered Turkey recently from Syria, was the attacker, but did not name him or provide other details of the investigation.

The blast occurred at around 10:15 a.m. in the heart of Sultanahmet, one of the most heavily trafficked districts in the historic city, steps from monuments commemorating the three empires — Roman, Byzantine, and Ottoman — of which the former Constantinople, now Istanbul, was the capital.

The attack, while less deadly than two others in Turkey last year, was arguably more resonant, at is it seemed unconnected to Turkish domestic politics and intended to sow fear and damage the country’s $30 billion tourism industry, already hurt by a drop in Russian visitors since Turkey shot down a Russian warplane near the Syrian border in November.

The attack could complicate President Recep Tayyip Erdogan’s cooperation with the European Union in stemming the flow of migrants from Syria entering through Turkey. The 28-nation bloc has offered 3 billion euros ($3.2 billion) to aid the 2 million Syrians in Turkey and to slow the exodus. Erdogan may now face domestic pressure to be less receptive to new refugees, and a greater incentive to turn a blind eye to those seeking to travel onward to Europe.

Already the country has effectively shut its southern border with Syria to new refugees, and last week it instituted new visa regulations for Syrians arriving by air, a decision that stranded hundreds at the airport in Beirut.

As the Syrian civil war has metastasized over the last five years, Turkey — determined to see President Bashar Assad ousted — has supported rebel groups, offering its territory as a transit route for fighters and weapons. Turkey has faced heavy criticism from its Western allies, including the United States, who accuse it of enabling the rise of the Islamic State, also known as ISIS or ISIL.

Only recently, analysts say, has Turkey seemed determined to clamp down on the group, conducting raids against Islamic State cells in Turkey and building a wall on a portion of its southern border with Syria opposite Islamic State territory.

Erdogan’s Syria policy has been deeply unpopular among the Turkish public — and the attack on Tuesday was likely to make it even more unpopular. But his party secured four more years in power in a snap election in November.

Germans accounted for 5.4 million visits to Turkey last year — or about 1 in 6 of all visits by foreigners.

“The terrorists are enemies of all free people — indeed, they are enemies of all humanity,’’ the German chancellor, Angela Merkel, said Tuesday in Berlin.

“We are in close solidarity with the people of Turkey,’’ she said, adding: “I mourn for our compatriots.’’

Sultanahmet, where the attack occurred, is home to some of Istanbul’s most visited monuments, including a Byzantine-era former hippodrome, or racetrack; the Hagia Sophia, a sixth-century Greek Orthodox basilica and now a museum; the Blue Mosque; and the Topkapi Palace, built by the Ottoman sultans.

The explosion was detonated close to the German Fountain, a gazebo-style structure that commemorates a visit by Kaiser Wilhelm II in 1898. The blast left several bodies around the base of an Egyptian obelisk that was carved around 1490 B.C. and was brought to the city in A.D. 390 by the Roman emperor Theodosius.

“I was in the basement checking the stocks when I heard a huge bang, and the whole building shook,’’ said Fehmi Ozyurt, a local leather vendor. “We all ran out and could see bodies on the floor, but we were too scared to get close in case there was another explosion. We’ve been through this before in Sultanahmet, so we expect the worst — that it’s a suicide bomber again.’’

Last January, a Russian citizen with possible ties to the Islamic State blew herself up at a police station in the Sultanahmet area, killing an officer.

“Tourism had already dried up after last year’s explosion, but after this it’s game over,’’ said Ayse Demir, 36, a shopkeeper at a local arts and crafts shop. “No one is going to risk their lives for shopping and history.’’

After the attack Tuesday, the German Foreign Office issued a statement warning tourists to stay away from public spaces.

“Travelers in Istanbul are urgently advised to temporarily avoid crowds, even on public squares and outside tourist attractions,’’ the statement said. “One has to continue to expect political tensions, violent confrontations, and terrorist attacks across the country.’’

The German foreign minister, Frank-Walter Steinmeier, called the attack a “barbaric, cowardly act of terrorism.’’

“For us, these are very difficult hours of sadness and horror,’’ he said at a news conference on Tuesday evening. “For many years, we Germans have not been hit so hard by terrorism as in Istanbul today.’’