KABUL: Suspected Taliban fighters fired a rocket into a hospital in Afghanistan on Wednesday, sparking a blaze that caused extensive damage and destroyed COVID-19 vaccines though there were no reports of casualties, government officials said.

In northern Afghanistan, the Taliban captured the town of Shir Khan Bandar, a dry port on the border with Tajikistan, sending customs worker and members of the security forces fleeing to safety over the border.

Fighting between government forces and the insurgents has surged in recent weeks, with the militants gaining control of more territory as the last U.S.-led international forces prepare to leave after two decades of fighting.

Taliban spokesmen Zabihullah Mujahid denied responsibility for the attack on the hospital in the eastern province of Kunar, which a provincial health director said resulted in the loss of crucial supplies.

"Different types of vaccine, including doses meant to fight polio and COVID-19 were destroyed in the fire," said Kunar health official Aziz Safai.

Afghanistan has reported 4,366 deaths due to COVID-19 infections and 107,957 cases, as of Wednesday.

Many health officials say the real number of coronavirus infections is likely much higher but many cases are not being detected because of little testing.

The virus has been spreading as insecurity has been growing, especially since May 1 when the United States began the final stages of its troop withdrawal and the Taliban stepped up attacks on government forces.

Tajikistan's border guard service said in a statement late on Tuesday it had allowed 134 Afghan servicemen to retreat into Tajikistan from Shir Khan Bandar, about 50 km (30 miles) from the city of Kunduz.

The Taliban seized ammunition and armoured vehicles in the town after Afghan authorities surrendered it to the advancing insurgents, Afghan officials said.

The loss of the trading town will be a blow to the U.S.-backed government as it struggles to stop Taliban advances in different parts of the country.