INCREASING levels of violence are threatening to derail intra-Afghan peace talks, United States special envoy Zalmay Khalilzad warned on Monday after renewed fighting in Helmand province.

US forces have been accused of carrying out air strikes in the southern province, which is a known Taliban stronghold.

The Islamists agreed to stop attacks on Afghan government targets on condition that the US stops its bombing campaign.

But the Taliban is believed to be behind a suicide car bombing on Sunday which killed at least 13 people and injured about 120 in the western Ghor province.

“Violence has stalked Afghans for far too long. It has robbed far too many Afghans of their loved ones,” Mr Khalilzad said. “The tragedy in Ghor today is the most recent example.

“The belief that says violence must escalate to win concessions at the negotiating table is very risky. Such an approach can undermine the peace process and repeats past miscalculations by Afghan leaders,” he added.

The Taliban, which has not claimed responsibility for the car bombing, said that the US air strikes were the catalyst for such violence.

In a statement, the Islamists warned that “all responsibility and consequences from continuation of such actions shall fall squarely on the shoulders of the American side.”

The government’s Helmand spokesman Omer Zwak said that gun battles were still taking place between the Islamists and government forces today.

The Afghan air force had conducted what it described as “limited air strikes” in support of its ground troops.

Peace talks between the Afghan government and Taliban representatives started in September, just over six months after the US signed a deal with the Islamists after 19 years of war and occupation.

US troops have started to leave Afghanistan as agreed in the February deal, which also led to the release of thousands of Taliban prisoners.