A suicide attacker detonated a bomb on Istanbul's main pedestrian shopping street on Saturday, killing five people, the city's governor said. Turkey's health minister said 36 people were wounded in the attack including 12 foreign nationals.
Governor Vasip Sahin said the explosion occurred outside a local government office on Istiklal Street, which is also home to cafes, restaurants and foreign consulate buildings. Sahin said one of wounded victims died in hospital and that the attacker was among the dead.
Turkey's health minister, Mehmet Muezzinoglu, did not provide information on the nationalities of the injured foreigners. But the private Dogan news agency said at least three of the injured are Israeli nationals and that the wounded included two children. And private NTV said at least one Iranian was among the injured.
The Israeli foreign ministry confirmed Israeli nationals were injured but did not provide details.
Police swiftly sealed off the area as ambulances and a forensic team rushed to the scene. Normally packed cafes were either closed or virtually empty, with business owners in the areas making frantic calls to check in with their loved ones and assure them of their safety.
Turkey was already on edge following two recent suicide car bomb attacks in the capital, Ankara, which were claimed by a Kurdish militant group, which is an off-shoot of the outlawed Kurdistan Workers' Party, or PKK. The most recent attack, on March 13, targeted a line of bus stops on Ankara's busiest street and killed 37 including two bombers.
"It was one loud explosion," said Muhammed Fatur, a Syrian who works at a butcher shop near the scene of Saturday's explosion. "Police came to the scene and sealed off the area."
Turkish Prime Minister Ahmet Davutoglu was convening a security meeting in Istanbul following the attack. There was no immediate claim of responsibility.
Cengiz Fidaner, who owns a cafe on a side street near the explosion site, told AP "the explosion was not so big but I felt it in my heart because our people died. They want a war but our people want peace. This is because of Newroz."
Turkey had heightened security in Ankara and Istanbul in the run-up to a Kurdish spring festival of Newroz on March 21, which Kurds in Turkey traditionally use to assert their ethnic identity and demand greater rights.
The German consulate, located in the same neighborhood as the blast, had been closed in recent days over security concerns.
Hours after Saturday's attack, the German Foreign Ministry urged travelers visiting Istanbul to stay in their hotels.
The ministry said in a statement that travelers should follow news reports and further German government advice, and heed the instructions of Turkish security forces.
The U.S. embassy in Turkey expressed sadness and shock over the attack on its Twitter account. "We mourn with the families of the lost, and we wish the injured a speedy recovery."
Fraser reported from Ankara. Ian Deitch in Jerusalem and Frank Jordans in Berlin contributed.