The leader of Turkey's main opposition party was attacked at a soldier's funeral in Ankara before security guards led him away, in the latest fallout from local elections three weeks ago.
Kemal Kilicdaroglu, head of the secularist Republican People's Party (CHP), attended a funeral for one of four Turkish soldiers killed on Friday in clashes with the outlawed Kurdistan Workers Party (PKK).
Turkish President Recep Tayyip Erdogan, whose AK Party wants the election results annulled in Istanbul, had repeatedly warned during last month's campaign that PKK members were among the CHP's list of candidates.
The clashes in the country's south-east on Friday prompted several pro-government newspapers to tie the soldiers' deaths to the party.
"PKK out" was among the slogans shouted at Mr Kilicdaroglu on Sunday.
Several TV broadcasters showed video in which Mr Kilicdaroglu was hit on the head at least twice as security guards and a police officer tried to keep dozens of men away. Some of the men were shouting "Shame on you".
Mr Kilicdaroglu edged through the crowd to a nearby house, outside of which a crowd chanted "PKK out".
More than an hour later, he was driven away in an armoured vehicle by police officers.
"They don't want me to go to our martyrs' funerals," Mr Kilicdaroglu, who escaped unhurt in 2016 when his convoy came under attack in the northeastern province of Artvin, told supporters outside CHP headquarters.
"They think I will step back if they attack me. I will not even take one step back."
Ankara's chief prosecutor, Yuksel Kocaman, said six attackers were identified and investigators were looking into whether the incident was related to terrorism, state-run news agency Anadolu reported.
"The incident is under control. Investigations have started," said Suleyman Soylu, Turkey's Interior Minister.
Justice Minister Abdulhamit Gul, also of the ruling AK Party, said: "We will not allow any kind of violence to cast a shadow on democratic politics."
Initial results and recounts showed that the CHP's mayoral candidates in Ankara and Istanbul defeated those from the AK Party, in painful losses for Mr Erdogan.
But the AKP has submitted two petitions to cancel and re-run the vote in Istanbul, claiming irregularities and illegal votes and voters.
Mr Kilicdaroglu was attending the funeral of soldier Yener Kirikci, who was among those killed on Friday when PKK insurgents attacked a military base in the mountainous Hakkari province near the Iraq border.
The Turkish military said six other soldiers were wounded and 20 PKK members killed in the clashes.
The PKK has waged an insurgency for autonomy in Turkey's largely Kurdish south-east since 1984, and is deemed a terrorist organisation by Turkey, the US and the EU.
One pro-government newspaper, Gunes, ran a headline on Sunday that said: "Six dead and four wounded. Are you happy Ekrem?", referring to the CHP's new Mayor of Istanbul, Ekrem Imamoglu.
The High Election Board has not yet ruled on the AKP's challenges, but Mr Imamoglu took office on Wednesday.
"Those who carried out the attack are not our citizens. Those who did this acted on orders," he told an Istanbul crowd on Sunday.
