KABUL (Reuters) - Afghan security forces backed by air strikes have been fighting to retake a district in the western province of Ghor since it fell to the Taliban earlier this week, officials said on Thursday.

The insurgents took control of the district center of Taywara - the main town of the rural area - on Sunday as part of a broad push that saw heavy fighting across much of the country.

Since then, government forces have pushed back. Local police spokesman Nazami, who like many Afghans goes by one name, said “large parts of the district” had been retaken in an operation involving hundreds of Afghan troops backed by local militia forces and air power.

U.S. military headquarters in Kabul said it had not conducted any strikes in Ghor. “All of the strikes were taken by the Afghan Air Force,” spokesman Capt. Bill Salvin said in an emailed statement. “That is a demonstration of the AAF’s growing capability to support (Afghan) troops on the ground.”

Local Governor Naser Khazeh said fighting had been difficult because roads to the district had been heavily mined and Taliban fighters were firing from civilian houses. He said government forces were close to the district center and the whole Taywara district should be retaken by the end of the week.

Security forces have struggled to control Ghor, a remote mountain province with sharp ethnic and tribal divisions and illegal armed groups that operate with impunity.

The Taliban have long had a strong presence and more recently, Afghan security officials say, fighters loyal to Islamic State have established themselves in the province.

The Taliban, fighting to re-establish strict Islamic rule in Afghanistan since being driven from power by the U.S.-backed campaign of 2001, control or contest around 40 percent of the country and have stepped up their offensive over the past week.

Earlier this week, around 30 Afghan soldiers were killed when the insurgents took an outpost in the southern province of Kandahar and there has also been heavy fighting in the opium-rich province of Helmand as well as northern areas including Faryab, Baghlan and Badakshan.

The fighting comes as the United States continues to weigh its policy approach to Afghanistan. An additional 4,000 U.S. troops are expected to be sent to boost the training and advisory mission but an announcement has been delayed amid reports of disagreements within the administration.