More than 50 people have been killed in fighting in western Pakistan, including 34 in clashes near the Afghan border where security forces are searching for the leader of the Pakistani Taliban.

The Pakistani army said the ongoing anti-Taliban offensive in North Waziristan and the greater Swat valley killed 18 suspected militants in the last 24 hours.  A spokesman said 16 soldiers, including three officers, also were killed in the fighting.

Army officials said the Swat campaign is now entering its final phase and all of the main militant strongholds in the region have been cleared.  They said that although small areas of resistance remain, in the next week they expect a large number of the roughly 2.5 million people who fled the violence will begin to return home.

In other violence Monday, in South Waziristan, officials said a stray mortar shell hit a mosque during prayers, killing three civilians and wounding seven.  It is unclear who fired the shell.

To the north, in Kurram agency, local officials said 15 militants who were heading to Afghanistan were killed in a clash with local tribe members.  Officials said two tribesmen also were killed in the battle.

On Sunday, Pakistan's government announced bounties for information leading to the capture or death of Pakistani Taliban chief Baitullah Mehsud and 10 other senior militants.

Mehsud, based in South Waziristan, is blamed for scores of attacks against government and civilian targets, and is believed to be a key facilitator for al-Qaida fighters in Pakistan.  

The U.S. already has offered a $5 million bounty for Mehsud.

But despite the bounties and ongoing military offensive, Pakistan's army has not reported killing any top Taliban leaders in either the tribal areas or the greater Swat valley.