Armed men killed six Pakistani security personnel and wounded seven in a checkpoint attack in the country's northwest, a police official said Saturday.

The assault happened in Kurram district, where fierce sectarian fighting has killed at least 130 people during the past few weeks.

A ceasefire between the area's Sunni and Shiite communities is holding and Saturday's incident is not connected to the recent clashes.

Local official Saleem Khan said armed men attacked a Frontier Corps checkpoint in Bagam, 200 kilometers (125 miles) south of Peshawar city.

The wounded were taken to a military hospital. There was no immediate claim of responsibility for the attack.

Also Saturday, an intelligence official said an operation against the Pakistani Taliban in Tank district had killed 20 militants in the past 24 hours. The official spoke on condition of anonymity because he was not authorised to talk to the press. Among the dead is a commander, the official said.

The militants who were killed were involved in attacks on security forces, extortion and the targeted killings of civilians, the official said.

Kurram and Tank are both in Khyber Pakhtunkhwa province, which borders Afghanistan.