The Taliban attacked a third provincial capital in Afghanistan in less than a week, killing at least two civilians, an official said Friday as a U.S. envoy was back in Qatar for unexpected talks on a U.S.-Taliban deal he had described as complete just days earlier.

Farah provincial governor Mohammad Shoaib Sabet told The Associated Press that another 15 people were wounded in the latest attack, citing local hospitals, and that airstrikes had been carried out against the militant group. Small clashes continued in the city, he said.

This week's spike in violence, including two shattering Taliban car bombings in the capital, Kabul, comes after U.S. envoy Zalmay Khalilzad said he and the insurgents had reached a deal "in principle" that would begin a U.S. troop pullout in exchange for Taliban counterterror guarantees.

Khalilzad abruptly returned to Qatar, where the Taliban have a political office, from Kabul for more talks Thursday evening, even though earlier in the week he said the deal only needed President Donald Trump's approval to be final.

Objections to the agreement raised by the Afghan government and several former U.S. ambassadors to Afghanistan, and the death of a U.S. service member in the latest Kabul bombing on Thursday, have increased pressure on Khalilzad in recent days.

House Foreign Affairs Committee Chairman Eliot Engel has demanded that the envoy testify before the House committee about the negotiations, saying that "I do not consider your testimony at this hearing optional."

The Taliban have explained their surge in deadly attacks — including on the capitals of northern Kunduz and Baghlan provinces last weekend — as necessary to give them a stronger negotiating position in talks with the U.S., a stance that has appalled Afghans and others as scores of civilians are killed.

One Farah resident, Shams Noorzai, said the Taliban on Friday had seized an army recruitment center close to the city's main police headquarters and set it on fire. All shops had closed, he said, and some people were trying to flee. It was at least the third time the Taliban have attacked the city, the capital of Farah province, in the past four years.

The governor later said security forces had re-taken the recruitment center.

Fighting resumed in at least one part of Kunduz city and two outlying districts on Friday, with some residents trying to flee again, provincial council head Mohammad Yousuf Ayubi said.

Few details have emerged from the nine rounds of U.S.-Taliban talks over nearly a year. Khalilzad has said the first 5,000 U.S. troops would withdraw from five bases in Afghanistan within 135 days of a final deal. Between 14,000 and 13,000 troops are currently in the country.

However, the Taliban want all of the approximately 20,000 U.S. and NATO troops out of Afghanistan as soon as possible.

The U.S. for its part seeks Taliban guarantees that they will not allow Afghanistan to become a haven from which extremist groups such as al-Qaida and the local affiliate of the Daesh terror group can launch global attacks.