Pakistan has ordered its army to enter a remote area of the country and attack the nation's leading Taliban commander.

The news of the operation in South Waziristan, rumoured for weeks, came hours after a suspected US missile strike killed five alleged militants.

The move is expected to please Washington, which wants Pakistan to eliminate havens for militants leaving Afghanistan and which considers South Waziristan a particularly troublesome hideout for al Qaeda.

Owais Ghani, the governor of North West Frontier Province, said the government felt it had no choice but to resort to force against Pakistani Taliban chief Baitullah Mehsud and his network .

"Baitullah Mehsud is the root cause of all evils," Mr Ghani said, referring to the spate of suicide bombings that has shaken Pakistan in recent days.

"The government has decided that to secure the innocent citizens from terrorists, a meaningful, durable and complete action is to be taken."

Intelligence officials said the army and Taliban were already fighting in the Spinkai Raghzai area of South Waziristan - part of Pakistan's semi-autonomous tribal belt.

The area is a possible hide-out of al Qaeda leader Osama bin Laden.