Some 20,000 protestors took to Istanbul's central Taksim square on Sunday to commemorate the 20th anniversary of one of the bloodiest incidents of Azerbaijan's war with Armenia over disputed Nagorny Karabakh.
Azerbaijan says 613 people died when Armenian troops attacked the village of Khojaly in Karabakh in 1992 in what Baku describes as "genocide", although Yerevan strongly rejects this.
In Istanbul, demonstrators waving Turkish and Azerbaijani flags chanted slogans and unfurled banners "Stop Armenian aggression," "Do not forget Turkic people genocide by Armenian gangs in southern Azerbaijan," and "Karabakh is Turkish, and will remain Turkish."
One protestor was seen wearing a T-shirt that read "Do not remain silent to Armenian lies."
A number of associations promoting friendship between Turkey and Azerbaijan as well as far-right and Islamist political parties and Interior Minister Idris Naim Sahin joined the demonstration.
Police put the number of protestors at around 20,000.
"We came here because of the atrocities committed in Khojaly in Nagorny Karabakh, because of the genocide committed by the Armenians there. We want the entire world to know about that," one of the protestors, Sultan Okumus, told AFP.
Armenian separatists backed by Yerevan seized Karabakh from Azerbaijan during a 1990s war that left some 30,000 people dead.
Armenia rejects Azerbaijan's version of events, denying that its forces massacred innocent civilians, disputing the number of people that died and blaming Baku for the killings.
Despite years of internationally-mediated talks since the 1994 ceasefire, the ex-Soviet enemies have not signed a final peace deal and soldiers are frequently killed in skirmishes along the Karabakh frontline.
Turkey and Azerbaijan, traditional allies, have stepped up efforts to raise international awareness of Khojaly amid Armenian diaspora's continuing attempt for recognition of the 1915 killings of Armenians at the hands of the Ottoman Empire as genocide.
France has recently passed a bill outlawing denial of the Armenian genocide which drew fury from Turkey but the legislation was put on hold after opponents demanded it be reviewed by the French Constitutional Council.
In Istanbul, police deployed armoured vehicles to protect the French consulate, about 100 metres (yards) from Taksim square.
Some protestors also chanted slogans against France. "People of France accepted the Armenian lie, they passed a law and they judged history," one of them told AFP.
Another demonstrator Emine Sonmez, wife of a military personnel, said: "There was no Armenian genocide! People must study history!"
Protestors later dispersed without any incident.