LASHKAR GAH, Afghanistan: Afghan forces are battling to hold Marjah district center in the volatile southern province of Helmand that Taliban insurgents have cut off as part of a months-long campaign in which they have taken three districts and threatened the regional capital.

Helmand police chief Abdul Rahman Sarjang said on Sunday security forces were holding on in the governor’s compound and police and army headquarters but that surrounding areas were all in the hands of the insurgents.

“Afghan police and army have a presence in Marjah district center and the rest is controlled by Taliban,” Sarjang said.

Helmand, an arid, semi-desert region and major center of opium cultivation, has long been one of the Taliban’s heartlands and they have put increasing pressure on security forces since the withdrawal of international troops from combat last year.

Major Taliban attacks in Kandahar and the capital Kabul last week underlined the Islamist movement’s ability to strike high-profile targets and heaped pressure on the government of President Ashraf Ghani. But its steady advances in Helmand pose a potentially more serious threat to the US-backed government.