The Taliban have seized a police base in northern Afghanistan and captured scores of officers after three days of fighting, officials say.

More than 100 officers surrendered at the base in Badakhshan province. They were released after reportedly handing over their weapons.

The surrender was the largest by Afghan security forces since Nato ended its combat mission in December.

The Taliban have stepped up attacks during their annual spring offensive.

A police spokesman said the officers were freed following a deal between the militants and the local police commanders who surrendered on Saturday evening.

Some officials blamed the central government for failing to send reinforcements to break the siege by the militants.

The base, in the province's Wardoj district, was cut off after heavy rains destroyed roads into the area, said Badakhshan police chief General Baba Jan.

It was not clear why reinforcements were not flown into the area, though the province's steep valleys often make aircraft landings difficult.

The Taliban issued a statement saying it had released the 110 police officers, their local commander and the head of the local border police after making an agreement.