Ankara: Turkey declared an open-ended curfew in Diyarbakir, the largest city in its Kurdish-dominated southeast, after PKK militants killed two policemen in mounting pre-election violence.

Three other policemen were wounded when the Kurdish militants attacked an armoured police vehicle in the city’s downtown Sur district, state-run Anadolu news agency reported. Anti-terrorism police, backed by helicopters, exchanged fire with the separatist rebels, and citizens were ordered to stay indoors until further notice, it said.

Turks are set to go to the ballot box on November 1 for the second time in six months after June elections failed to produce either a clear winner or a governing coalition. The outcome of the vote thrust the country into deeper political and economic turmoil, and was followed by a surge in clashes between Kurdish militants and Turkish security forces. According to unconfirmed official figures, more than 1,180 people have been killed in the fighting since early July.

Prime Minister Ahmet Davutoglu last week dismissed warnings from the pro-Kurdish HDP party that spiralling violence could prevent voting in the southeast.

The government, escalating its military drive against the militants, has declared closed military zones in areas of the southeast. HDP executive committee member Ali Urkut said more than 125 such zones had been declared as of August 27, and voiced concern in a letter to the Supreme Election Board that the government may use the areas to move ballot boxes elsewhere in the region.

The government has accused PKK of coercing people to vote for HDP in the June elections, when the pro-Kurdish party won 13 per cent of the vote, stripping the governing AKP of its parliamentary majority for the first time since 2002. Turkish President Recep Tayyip Erdogan declared a repeat vote after coalition talks collapsed.