Turkey's state-run media say an attack on a civilian minibus in eastern Turkey has killed four people and injured many others. Anatolia news agency says assailants opened fire on the bus in the eastern province of Van on Friday. Anatolia says the motivation for the attack is not yet known. But another local news agency, Dogan, says a blood feud was behind it. Kurdish rebels fighting for self-rule in southeastern and eastern parts of Turkey have in the past staged attacks on civilian vehicles carrying soldiers. It was unclear whether there were any military personnel involved in Friday's attack.