By Daren Butler
ISTANBUL (Reuters) - Turkish police fired tear gas and water cannon to disperse crowds protesting against a rally by the pro-Kurdish Peoples' Democratic Party (HDP) in eastern Turkey on Thursday, ahead of weekend parliamentary elections.
The clashes are the latest in a series of incidents to mar campaigning in the run-up to Sunday's highly charged vote, in which the HDP is hoping to deal a heavy blow to President Tayyip Erdogan's hopes of a more powerful presidency by passing the 10 percent threshold required to enter parliament.
Hundreds of youths, some carrying Turkish flags and some chanting "God is greatest", sought to reach the square in the city of Erzurum, a stronghold of the Islamist-rooted AKP, where HDP co-leader Selahattin Demirtas was speaking, video footage from Dogan news agency showed.
Some protesters pushed down barriers before police forced them back with water cannon just tens of metres from the rally, which was attended by several thousand HDP supporters.
A van decorated with HDP flags was set ablaze and its driver sustained burns before fleeing, Hurriyet reported. It said a police officer suffered a head wound and some protesters were also hurt.
The party is running for parliament for the first time, amid efforts to end a 30-year insurgency by the militant Kurdistan Workers Party (PKK).
Critics of HDP, particularly Turkish nationalists, accuse it of links to the PKK.
Unidentified assailants fired on an HDP campaign minibus in the mainly Kurdish southeast's Bingol province on Wednesday, killing the driver, the provincial governor's office said.
In May, simultaneous bomb blasts damaged HDP offices in two eastern Turkish cities, wounding six people.
HDP officials say there have been dozens of assaults against the party in the run-up to polling day.
The party is attempting to widen its support base beyond its core Kurdish vote, appealing to centre-left sympathisers to help it reach the 10 percent threshold needed to enter the assembly.
If it succeeds, as recent polls suggest, it would seriously complicate AKP's hopes of gaining a majority large enough to change the constitution and furnish President Tayyip Erdogan with the sweeping executive powers he seeks.