Pakistani security officials say at least 40 militants have been killed in air strikes in northwestern Pakistan.

Military officials Saturday said fighter jets started pounding militant hideouts in the Swat Valley late Friday, to try to flush militants from the area.

Swat was a major tourist valley until pro-Taliban cleric Maulana Fazlullah tried to impose Islamic rule in the tribal region.  The government struck a peace deal with Fazlullah in May, but militants have continued their attacks.

Elsewhere in the northwest, residents and officials say a missile fired from across the border in Afghanistan has hit a suspected militant hideout in the town of Wana, in South Waziristan.  Officials say at least five people were killed.  A Pakistani army spokesman, Major Murad Khan, said he was aware of the explosion, but could not confirm whether it was caused by a missile.

It was not immediately clear who was responsible for the attack, but U.S.-operated pilotless drone aircraft have launched attacks in Pakistan's border region in recent months, killing militants.

The military operation in Swat follows the Pakistani government's offensive against Taliban and al-Qaida-linked militants in Bajaur tribal region.

More than 500 militants have been killed and Red Cross officials say 200,000 people - mostly women and children - have been displaced since the fighting in Bajaur began several weeks ago.

A Red Cross spokeswoman, Carla Haddad, says the aid organization plans to deliver large quantities of food and other supplies to those living in makeshift camps in the tribal areas of Dir and Mardan in North West Frontier Province.

Some information for this report was provided by AFP, AP and Reuters.