The attack happened at the entrance of a hospital in Kotlan Saidan village in Pakistan (Reuters)

A female suicide bomber killed six people -- including two policemen -- in Pakistan's restive northwest Sunday in an attack claimed by the Taliban, officials said.

The attack happened at the entrance of a hospital in Kotlan Saidan village on the outskirts of the northwestern city of Dera Ismail Khan.

District police chief Salim Riaz told AFP that police were helping move the bodies of two of their colleagues -- who had been shot dead by terrorists on Saturday -- when the suicide bomber struck.

"The female bomber, aged around 28 years, came on foot and blew herself up, killing two policemen and four civilians and wounding 13 others," he said.

The injured included eight policemen and five civilians.

Another local police official, Malik Habib, confirmed the attack and casualty figures and said officers later recovered the mutilated head of the bomber.

Tehreek-e-Taliban Pakistan spokesman Muhammad Khurasani claimed responsibility for the attack in a statement sent to local media.

Pakistan has seen an improvement in security in recent years, but low-level attacks are still carried out with devastating regularity -- often targeting security forces in the northwest and the tribal regions bordering Afghanistan.