ISTANBUL (AFP) -- A Turkish court Thursday charged another man over the murder of journalist Hrant Dink, bringing to eight the number of suspects arrested in the investigation, the Anatolia news agency reported.

The court jailed Tuncay Uzundal, reportedly a friend of one of the other suspects, on charges of involvement in homicide and belonging to an armed criminal organization, judicial officials told Anatolia.

Another detainee questioned by prosecutors was released.

Among the eight suspects is the alleged assailant, 17-year-old Ogun Samast, a jobless secondary school graduate who, officials say, has confessed to gunning down Dink, 52, on January 19 outside the offices of his bilingual Turkish-Armenian weekly Agos in downtown Istanbul.

Interior ministry inspectors, meanwhile, were looking into allegations that the police had received a tip-off last year about a plot to kill Dink being organized in Trabzon, from where all suspects come, but did not follow up on the intelligence.

The tip-off reportedly came from one of the suspects currently in jail who had been recruited as a police informer after a bomb blast outside a McDonald's restaurant in Trabzon, for which Samast's alleged instigator, also among the eight suspects, served 11 months in jail.

Journalists and politicians in Turkey have expressed outrage at the killing, which many described as a political assassination, while the U.S., EU, France, and several human rights groups also voiced shock and condemnation.

Dink had received multiple death threats from nationalists because of his views on the mass killings of Armenians during the final days of the Ottoman Empire.