Five soldiers have been killed and eight others injured when a bomb planted by Kurdish guerrillas exploded on a train in eastern Turkey, military officials said.
A second train that travelled to the scene to provide assistance was fired on by fighters armed with rifles, an official said. It was not known whether there were any casualties in this attack.
The state-run Anatolian news agency said a postal train was targeted in the first attack.
The five dead and three of those injured were soldiers travelling on the train in Bingol province between the eastern towns of Elazig and Tatvan when the blast occurred around 10.15am (0715 GMT) on Saturday.
Kurdish rebels
One official said rebels from the separatist Kurdistan Workers Party (PKK) were believed to have laid C-4 plastic explosives on the track and triggered them by remote control. A military operation was launched to capture those responsible.
The blast toppled carriages, and work had begun to rescue people trapped inside, an official said. Around 100 people were on board the train at the time. The injured were being transported to hospital by helicopter.
More than 30,000 people have been killed in the PKK's armed campaign for self-rule in southeast Turkey since the group took up arms in 1984.
The clashes tailed off after PKK leader Abdullah Ocalan was captured and jailed in 1999, but there has been a resurgence of violence since the group called off a unilateral ceasefire last year.