Taliban fighters have seized control in much of the key city of Kunduz in northern Afghanistan, including government buildings and the police headquarters, a provincial council member said Sunday.

Ghulam Rabani Rabani said fighting between insurgents and government forces had taken place around the governor’s office and police headquarters but that later the Taliban had taken over the two buildings. They also had control of the main prison building in Kunduz, he said.

Rabani said fighting was continuing at the city's airport and other parts of the city. Kunduz is a strategic crossroads with good access to much of northern Afghanistan as well as the capital, Kabul, about 200 miles (335 kilometers) away.

The Taliban have also taken government buildings in the northern provincial capital of Sar-e Pul, driving officials out of the main city to a nearby military base, Mohammad Noor Rahmani, a provincial council member of Sar-e Pul province, said Sunday.

A Taliban offensive has gathered momentum in recent days, as the insurgents unleashed their forces across Afghanistan after the United States announced it would end its military mission in the country by the end of August.

On Friday, the insurgents captured their first provincial capital in years when they took control of Zaranj, on the border with Iran in Afghanistan's southern Nimroz province.

An Afghan security forces spokesperson said "extremely (heavy) fighting is going on" in Kunduz, as security forces fought to defend the city, regarded as a strategic prize as it lay at the gateway to mineral-rich northern provinces and Central Asia.

But a provincial lawmaker in Kunduz told Reuters the insurgents had taken key buildings in the city of 270,000 people, raising fears that it could be the latest to fall to the Taliban.

"Heavy clashes started yesterday afternoon, all government headquarters are in control of the Taliban, only the army base and the airport is with the ANDSF (Afghan security forces) from where they are resisting the Taliban," Amruddin Wali, a member of the Kunduz provincial assembly, said.

Taliban spokesperson Zabihullah Mujahid said the group had largely captured the province and were close to the airport.

Rohullah Ahmadzai, the spokesperson for the Ministry of Defence, said on Facebook that special forces were in Kunduz and had been conducting "clearance operations" in the city to take back media offices that the Taliban had captured.

Health officials in Kunduz said that 14 bodies, including those of women and children, and more than 30 injured people had been taken to hospital. In Sar-e Pul, Rahmani said, "Government headquarters, including the governor's house, police command, and the National Directorate of Security compound, are captured by the Taliban."

On Saturday, Taliban fighters entered the capital of Jawzjan province after sweeping through nine of 10 districts in the province. Several other of the country’s 34 provincial capitals are threatened as Taliban fighters sweep through large swaths of Afghanistan at a surprising speed.

Meanwhile, airstrikes damaged a health clinic and high school in the capital of southern Afghanistan's Helmand province, a provincial council member said Sunday.

A Defense Ministry statement confirmed that airstrikes were carried out in parts of the city of Lashkar Gah. It said forces targeted Taliban positions, killing 54 fighters and wounding 23 others. It made no mention of a clinic or school being bombed.

Majid Akhund, deputy chairperson of the Helmand provincial council, said airstrikes hit a health clinic and a school in the city's 7th police district late Saturday. But he said the area is under Taliban control so any casualties could have been caused by the Taliban there.

Dr. Ahmad Khan Weyar, an official from the Helmand public health department, said a nurse was killed when an airstrike hit a health clinic and a guard was also wounded.

"American invaders bombed and destroyed another hospital and school in Helmand," the Taliban said in a statement. It said Safyano Hospital and Muhammad Anwar Khan high school were bombed.

The clinic in Lashkar Gah was offering services mostly to nomads who were passing through the area, according to Akhund, but in recent days the area was under Taliban control and the Taliban may have been treated there.

Heavy fighting has taken place in and around Lashkar Gah and both U.S. and Afghan government air forces have conducted airstrikes in the city. The Taliban control nine of the city’s 10 police districts.