Turkey ? A group of men stopped a passenger bus and tossed gasoline bombs at it, sending the vehicle careening into pedestrians and killing three in Istanbul, Turkey’s largest city, on Sunday as pro-Kurdish riots continued to spread.

In the country’s heavily Kurdish southeast, a pro-Kurdish demonstrator was killed, and local officials blamed police for his death.

Clashes between Kurdish demonstrators and security forces have spread from the southeast to Istanbul, which has a large Kurdish population.

In the attack in Istanbul’s Bagcilar district, the driver reversed his flaming vehicle onto a sidewalk after the bombing, running down a group of people nearby, police said. At least two of those killed were elderly women, and police said they suspected Kurdish militants were behind the attack.