Five militants killed in Pakistan explosion

At least five militants were killed Monday and four injured in an explosion in Pakistan, media report said.

Official sources said the blast occurred in a militant post in Khyber Agency's remote Tirah valley, Dawn online reported.

Khyber is part of Pakistan's semi-autonomous tribal belt on the Afghanistan border.

The Taliban and other Al Qaeda-linked groups, who stage attacks in both the countries, are known to have strongholds in the zone.