Taliban fighters with heavy weapons and night-vision equipment fought their way close to the center of the western city of Farah yesterday, as Afghan government forces battled to keep control, officials and residents said.

Residents of Farah, capital of the province of the same name, have warned for months the city was vulnerable and the attack appeared to threaten a repeat of the Taliban's capture of the northern city of Kunduz, which fell briefly in 2015.

"The Taliban are moving very fast, if the government does not take serious and speedy action, the province is going to collapse to Taliban," said Hamidullah, a resident of the city reached by telephone.

Mohammad Radmanish, a spokesman for the defense ministry in Kabul, said security forces from neighboring provinces had been ordered to Farah to protect civilians and government buildings and said the Taliban had been pushed out of the city. "Fortunately, Special Forces and commandos are in the city and there is no danger of it falling," he said, adding that the Afghan air force was attacking Taliban positions.

The fighting adds to the growing number of crisis points around Afghanistan since the Taliban began their annual spring offensive last month, including a series of deadly suicide attacks in the capital, Kabul.

Although the insurgents have been unable to take and hold any provincial center, they are active across Afghanistan and the government has firm control over no more than 56 percent of the country, according to U.S. estimates.

The United States has boosted its assistance to the government under a new strategy announced by President Donald Trump last year, sending thousands of additional troops and advisers and stepping up air strikes to support Afghan forces. Although U.S. commanders have been relatively upbeat about improvements in the performance of Afghan forces, the Taliban appear to have made significant gains this year. Farah, a remote and sparsely populated province on the border with Iran, has seen months of heavy fighting, with hundreds of police and soldiers killed and severe losses inflicted even on elite special forces units.