PESHAWAR, Pakistan - Three days of clashes between security forces and militants in northwest Pakistan near the Afghan border left more than 56 militants and six soldiers dead, the military said Tuesday.

There was no way to independently confirm the casualty figures because access to the affected regions was restricted for journalists.

The vast majority of the deaths occurred during a two-day operation Sunday and Monday in the Maidan area of Lower Dir, a region bordering the Swat Valley where the army has been wrapping up an offensive against Taliban militants.

More than 50 militants died in the clashes, said Maj. Fazlur Rahman, spokesman for the paramilitary Frontier Corps. The army also confirmed the toll.

Rahman said the operation was aimed at clearing pockets of resistance in Maidan, and those killed included militants who fled the Swat area during the army's offensive.

In a statement, the army also said it arrested five militants disguised in burqas who tried to flee a search operation conducted in the previous 24 hours in Swat. Five other militants and three soldiers were killed in the latest clashes in the valley.

Another military search operation found the bodies of 10 suspected militants in a cave in Swat, the army said in Tuesday's statement.

The violence shows security remains fragile in the northwest, even as thousands of refugees head back to Swat as part of a government repatriation program for the roughly 2 million people uprooted by the military campaign that started in late April.

The military has said it killed more than 1,700 suspected militants in Swat and surrounding districts, but the toll has been impossible to verify independently. Pakistani authorities have not given any figures for civilian casualties.

Pakistan's military is also preparing a similar campaign in the South Waziristan tribal region targeting the Pakistani Taliban chief, Baitullah Mehsud.

The U.S. supports the operations, saying Islamabad must eliminate militant safe havens for its own stability's sake as well as to lessen the threat those fighters pose to the U.S.-led war in neighbouring Afghanistan.

The Swat campaign drove some 2 million people from their homes, according to the United Nations. The military recently declared the region largely cleared of militants, and thousands have been returning home.

On Monday, the government officially closed two camps near the city of Mardan that had housed about 20,000 people, said Mian Iftikhar Hussain, the information minister for North West Frontier Province.