Turkish authorities have lifted a curfew on the mainly Kurdish city Cizre, 12 hours after re-imposing it, BBC News reports.

The city had been under curfew since 4 September. It was lifted on Saturday, September 12 only to be re-imposed a day later.

The measure was introduced due to fighting with the outlawed Kurdish PKK group, officials say. The pro-Kurdish HDP party says 21 civilians died.

Violence has surged between Turkey and the PKK since a ceasefire collapsed in July. Over the weekend, HDP party leader Selahattin Demirtas urged a return to peace talks.

"We call on all parties to take into account the public's expectations," he said.

Turkey has described Cizre as a hotbed of PKK activity.

But critics accuse President Recep Tayyip Erdogan of renewing violence to curb support for the HDP, whose 14% share of the vote in June elections cost the governing AKP its majority in parliament.

The government denies the accusations. Many people fear the clashes will mount as snap elections scheduled for November draw closer.