By Omer Berberoglu and Daren Butler
ISTANBUL (Reuters) - A doctored video splicing footage of President Tayyip Erdogan's main rival and a Kurdish militant chief and showing them uttering the same slogan has raised tensions ahead of a vote on Sunday marred by accusations of smear campaigns.
Opinion polls show Kemal Kilicdaroglu ahead of Erdogan. In a move seen boosting the president's rival, another of the four candidates withdrew from the race on Thursday, saying he was the target of election smears.
In his campaign, Erdogan has repeatedly suggested links between the outlawed Kurdistan Workers Party (PKK) and the opposition alliance, without providing evidence, tapping into nationalist hostility towards the PKK.
In a rally attended by hundreds of thousands last Sunday, Erdogan pointed to a screen and urged followers to watch a "very important" video that began by showing a smiling Kilicdaroglu appealing to voters, "Come on, together to the ballot box."
The brief video then switches to top PKK commander Murat Karayilan, apparently also saying, "Come on" alongside a group of militants clapping along to Kilicdaroglu's campaign song. Kilicdaroglu's picture is then superimposed over them.
"Would my patriotic and homegrown citizens vote for them?" Erdogan asked rhetorically as the video was shown.
The Kilicdaroglu footage was taken from one of his campaign videos while the PKK images came from a video released online 10 months ago in which the militants cheer their jailed leader.
Erdogan commented on the doctored video in a gathering with students aired on Turkish channels on Thursday evening.
"Kilicdaroglu has the man at the head of the terrorist group behind him. He says 'come on' and the other one says 'come one'," Erdogan said in the TV show.
Asked about the doctored video and Erdogan's use of it in campaigning, presidential officials declined to comment.
"What saddens me deeply is, that the language is being used by the president himself," Kilicdaroglu said in a Reuters interview on Friday, describing the video as a lie.
Separately, he tweeted, "I say to young people, there is someone shamelessly aiming black propaganda at you with doctored content."
Kilicdaroglu also voiced concerns on Thursday evening when he accused Russia of responsibility for the release of fake material on social media ahead of the vote, and he told Reuters on Friday he had concrete evidence of this.
The Kremlin said the allegations that Russia had interfered in the election were false and had been concocted by liars.
The PKK, deemed a terrorist group by Turkey and its Western allies, took up arms against the state in 1984. The fighting has killed more than 40,000 people.
Parliament's third biggest party, the pro-Kurdish HDP, is facing a potential ban over links to the PKK, which it denies. Erdogan frequently accuses the HDP of such ties.
The HDP has declared its support for Kilicdaroglu in the presidential election and is entering the parliamentary vote under the emblem of the small Green Left Party due to the closure threat.
(Additional reporting by Orhan Coskun, Huseyin Hayatsever and Ece Toksabay; writing by Daren Butler; editing by Mark Heinrich)