A prison guard was killed in an explosion on a bus in Turkey's north-west province of Bursa on Wednesday, Governor Yakup Canbolat said. Four other guards were injured in the explosion.
The attack occurred in the Osmangazi district, as the bus was taking the guards to a prison in the region.
It was not apparent who carried out the bombing, Mr Canbolat said. The attackers, he said, detonated a remote-controlled explosive device that was planted next to an electric pole when the bus carrying prison guard personnel drove past it.
One person was seriously injured in the explosion, while two or three others were injured but were discharged from hospital, he said.
There was no immediate claim of responsibility for the attack.
“All our security units are working on the issue from all sides. Hopefully, we'll ... capture the perpetrators as soon as possible,” Mr Canbolat said
He said there were about 30 people on the bus, and that all of them were taken to hospital as a precaution.
Kurdish militants, leftist extremist groups and ISIS militants have carried out similar attacks around the country in the past.
Agencies contributed to this report.
