Kurdish separatist fighters have attacked a police station in Turkey, killing five police officers and wounding nine in a clash in which three rebels were also killed, security sources said.

They said Saturday's assault took place in the southeastern province of Siirt and fighting continued late into Saturday night.

The attack comes at a time of heightened tension between the armed Kurdistan Workers' Party (PKK) and the Turkish military, which has launched air strikes and artillery barrages against suspected PKK bases in northern Iraq in retaliation for a spate of militant attacks inside Turkey.

Earlier this month, Idris Naim Sahin, Turkey's interior minister, said Ankara was preparing a possible ground operation in northern Iraq, depending on the result of talks with Iraq. The semi-autonomous government of Iraq's Kurdistan region has voiced stiff opposition to the proposed incursion.

After a clear victory in a June election, Tayyip Erdogan, the Turkish prime minister, vowed to press ahead with legal reforms addressing the 12-million-strong Kurdish minority's grievances.

But a wave of PKK attacks has raised the possibility of a return to a hardline government stance in the decades-old fight against the rebels, with Erdogan recently warning he had lost patience with the PKK.

The PKK, branded a terrorist group by Ankara, Washington and the European Union, took up arms against the Turkish state in 1984 to fight for Kurdish autonomy.

More than 40,000 people have died in the separatist insurgency.