Three people have been killed in an attack on a Turkish publishing house which prints Bibles and other Christian literature.
Reports said the victims' throats had been cut and that police had detained six people in connection with the incident on Wednesady at the Zirve publishing house in
Television pictures showed casualties being carried out of the building and one man being restrained by police.
Nationalists had previously held a demonstration outside the publishing house, accusing it of proselytising, the private Dogan news agency reported.
The Zirve publishing house has been the site of previous protests by nationalists accusing it of proselytising in this 99 per cent Muslim but secular country, the news agency said.
Zirve's general manager told CNN-Turk television that his employees had recently been threatened.
"We know that they have been receiving some threats," Hamza Ozant said, but could not say who made the threats.
The manner in which the victims were bound suggested that the attack could have been the work of a local Islamic extremist group, said commentators.
CNN-Turk said police were investigating the possible involvement of Turkish Hezbollah - a Kurdish Islamic organisation that aims to form a Muslim state in Turkey's Kurdish-dominated southeast.
Turkish Hezbollah - which has been known to “hog-tie” its victims while torturing them - takes its name from the better-known Lebanon-based Hezbollah, but has no formal links to it. Turkish authorities recently said they were witnessing an increase in the group's activities.