People hold posters of slain journalist Hrant Dink during a commemoration ceremony in Istanbul

Dozens of former Turkish public officials, including former police chiefs, went on trial Tuesday on charges of negligence over the murder of Turkish-Armenian journalist Hrant Dink in 2007 that sent shockwaves around the country.

The suspects face accusations of failing to uncover the plot to murder Dink, the editor-in-chief of the Turkish-Armenian bilingual weekly Agos and a passionate advocate of reconciliation between Turks and Armenians.

A total of 34 suspects -- including eight who are under arrest -- went on trial in the first hearing at the Istanbul criminal court, the state-run Anatolia news agency reported.

Among those on trial are the former national police intelligence chief Ramazan Akyurek, former Istanbul police chief Celalettin Cerrah and former Istanbul police intelligence chief Ilhan Guler.

Dink, 52, was shot dead with two bullets to the head in broad daylight outside the offices of Agos in central Istanbul on January 19, 2007.

Ogun Samast, then a 17-year-old jobless high-school dropout, confessed to the murder and was sentenced to almost 23 years in jail in 2011.

But the case grew into a wider scandal after it emerged that the security forces had been aware of a plot to kill Dink but failed to act.

Also among those on trial Tuesday was Ercan Demir, who was police intelligence chief of the Black Sea Trabzon region where the gunman came from.

Anatolia said that another prominent suspect, former top Istanbul police official Ali Fuat Yilmazer, was already under arrest as part of investigations into the outlawed group of the US-based preacher Fethullah Gulen, the arch enemy of President Reep Tayyip Erdogan.

There have been numerous indications that the authorities want to emphasise the alleged links between the suspects and Gulen, whose followers are the subject of a major nationwide crackdown.

Turkey's top court in July 2014 ruled that the investigation into the killing had been flawed, paving the way for the trial of the police officials.

Relations betweens Turks and Armenians are heavily burdened by history but a small community of Armenians still lives in Turkey, mainly in Istanbul.

Armenians accuse Ottoman forces during World War I of carrying out a genocide aimed at wiping out their forebears from Anatolia that left an estimated 1.5 million people dead.

But modern Turkey has always vehemently resisted terming the mass killings as genocide.