The military says troops are 'engaging' the militants Pervez Musharraf

Eight soldiers have been killed and 32 others wounded in raids on militant hideouts backed by artillery and helicopters, a military statement said.

Earlier troops had hit militant positions with artillery fire.

South and North Waziristan, adjoining the Afghan border, are strongholds of militants allied to the Taleban.

The military said that the militants had been killed in a series of raids on Wednesday and early on Thursday.

Thirty militants had been arrested from a number of hideouts near the Afghan border during the raids, the statement said.

Mastermind

In the latest fighting, militants are reported to have responded to the army artillery attacks by firing missiles at security positions.

Why Waziristan matters Army's tribal quagmire Profile: Baitullah Mehsud

There are reports of people moving out of the area and walking for miles to reach secure zones.

The government has set up a temporary camp for displaced people in the Tank district of North West Frontier Province, where tents and food have been made available.

Militant leader Baitullah Mehsud is based in South Waziristan and is accused of leading attacks by tribesmen on forts controlled by the army.

The authorities in Islamabad also accuse him of masterminding the murder of former Prime Minister Benazir Bhutto last month.

On Wednesday, a Pakistani senator said that Mr Mehsud was not involved in Ms Bhutto's killing.

Saleh Shah, an Islamist senator who represents Waziristan, says Mr Mehsud was not "in any way" involved.

He also rejected recent claims by the American Central Intelligence Agency that Mr Mehsud is involved with al-Qaeda.

"I don't know where these stories come from - about foreign fighters in the area," he said.

"I have never seen any Arab or Uzbeks in the area."