Police have arrested six people over the killing of the Russian ambassador, Turkish state media Anadolu Agency said on Tuesday.

On Monday a policeman had gunned down the Russian envoy Andrey Karlov at a photo exhibition in Ankara in full public view. According to media reports, the policeman shouted "Don't forget Aleppo!" as he gunned the envoy down. The policeman was identified as 22-year-old Mevlut Mert Altintas, who had worked for the Ankara riot police for around two years. He was later shot dead by members of Turkey's Special Forces.

His mother, father, sister and two other relatives were held in the western province of Aydin, while his flatmate in Ankara was also detained, the state-run Anadolu agency said.

The slogans that Altintas shouted, which were captured on video and circulated widely on social media, suggested he was aligned to a radical Islamist ideology, rather than that of Gulen, who preaches a message of interfaith dialogue.

"Don't forget Aleppo, don't forget Syria. You will not be able to feel safe for as long as our districts are not safe. Only death can take me from here," he shouted in Turkish.

Russia is the main coalition partner who is backing Syrian President Bashar-al-Assad in the ongoing conflict in Syria which had led to mass killings of people opposing Assad forces. Meanwhile, Turkish government is backing the opposite rebel faction in war-torn Syria.

The killing of Russian envoy is being seen as the reaction of recent bombing in rebel held Aleppo where hundreds of people were killed last week. The ongoing civil war between Assad forces and Sunni rebels have killed around 300,000 people and created a power vacuum exploited by Islamic State.

However, the conflict reached a potential turning point last week when Syrian forces ended rebel resistance in the northern city of Aleppo.

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