At least 11 people were killed and 36 injured when a car bomb targeted a police bus in the historic center of Istanbul, Vasip Sahin, the Istanbul governor told reporters.
The death toll included seven police officers and four civilians.
“Today at around 8:40, in our neighborhood of Vezneciler, an attack by a car bomb on a bus carrying our police was carried out,” Sahin said.
“As a result seven police (and) four civilians lost their lives. May God bless their souls. 36 people were injured. Three of them are in critical condition. Investigation is ongoing.”
Police established a security corridor in the area and then widened the perimeter, and urged people to vacate the area because a controlled explosion was due to be carried out.
Local media reported that the blast, which occurred in the middle of morning rush hour, was remotely detonated.
Ambulances were on the scene and have taken the wounded to nearby hospitals, according to state news agency Anadolu.
Images from the blast area in the Beyazit Vezneciler district showed security personnel at the scene and visible damage to vehicle and buildings.
So far, no group has taken responsibility for the bombing.
Latest attack
Turkey has been rocked by multiple terror attacks this year. Attacks carried out by both the Kurdish militants and ISIS have targeted the capital Ankara and tourism hub Istanbul.
The last car bomb was in Ankara in March. That attack took place near a crowded bus stop but militants who claimed the bombing said the intended target was nearby police officers.
Just six days later an ISIS suicide bomber detonated himself on one of Istanbul’s main streets, killing three Israelis and one Iranian tourist.