LASHKAR GAH, Afghanistan (Reuters) - Afghan forces backed by air strikes battled on Monday to recapture a district center in the western province of Farah, after Taliban fighters seized the town in an overnight attack that killed several policeman, regional officials said.

The fighting in Farah underlines the continuing strength of the Taliban movement, which controls or contests almost half of Afghanistan, and has so far rejected peace overtures from President Ashraf Ghani.

Nasrat Rahimi, a deputy spokesman of the interior ministry, said reinforcements had arrived in Anar Dara town and surrounded a group of Taliban fighters. Air strikes had killed 56 insurgent fighters, he said.

Eight police, including the local police commander had been killed and several wounded, he added.

The Taliban released pictures that appeared to show fighters in the town and a spokesman for the group, Qari Yousuf Ahmadi, said 15 policemen had been killed and several military vehicles seized, along with a large quantity of ammunition.

No comment was immediately available from U.S. military headquarters in Kabul.

Afghan and U.S. commanders have been relatively upbeat about the course of the war since U.S. President Donald Trump announced a new and more robust military strategy last year, with more air strikes and greater support for Afghan forces.

The fighting in Anar Dara came days after local officials said the Taliban had inflicted heavy losses on Afghan special forces in another district of Farah, an isolated region where the government has long struggled to control.

The pressure on Farah has grown as U.S. air strikes and Afghan army operations have inflicted heavy casualties on Taliban fighters in neighboring Helmand province, the country’s main opium-growing region and a heartland of the insurgency.

In January, the governor of Farah resigned, blaming political interference and corruption. Residents of Farah city have complained bitterly about security in the province, where some police units are alleged to collude with Taliban fighters, selling them weapons and ammunition.

Although they have failed to take any major provincial cities, the insurgents have several times seized district centers, even if they have often been driven off soon after by government reinforcements.

With the approach of milder spring weather, security officials have said they expect fighting to surge as the Taliban, fighting to drive out international forces and re-impose their version of strict Islamic law, step up pressure.

The U.S. military’s latest estimates from December show the Afghan government controls or has influence over 56 percent of districts, with insurgents controlling or contesting the rest.