UPDATE 2-Bomb blast hits police bus in southern Turkey, five wounded -governor

(Changes source, adds details on casualties)

ISTANBUL, Sept 25 (Reuters) - A bomb explosion ripped into a bus carrying Turkish police in the southern city of Adana on Wednesday morning and five people were slightly wounded including one police officer, the local governor's office said.

CNN Turk broadcast video of a badly damaged bus surrounded by debris and other damaged vehicles under a pedestrian overpass in the Yuregir district of Adana, near Turkey's Mediterranean coast.

The wounded were in good condition and an investigation has been launched into the blast, the Adana Governor's office said in a statement on its website.

Security sources said ambulances took the wounded to hospitals in the area. Armed police sealed off the area and were examining the scene. It was not clear who might be behind the attack.

Kurdish, Islamist and leftist militants have all carried out bomb attacks in Turkey in the past. (Reporting by Daren Butler; Editing by Kim Coghill and Jonathan Spicer)