At least 12 fighters including foreigners have been killed in a raid by Pakistani gunship helicopters in a remote tribal area near the Afghan border, according to the Pakistan military.

Mortars were fired during Tuesday's attack at a hideout some 20km west of Miranshah, the main town in the North Waziristan tribal district.

"There are unconfirmed reports that six to eight Arabs, Tajiks and Chechens were among the militants killed in the operation," Major-General Waheed Arshad, a senior military spokesman, said on Wednesday.

He said around 10 fighters were also wounded.

Hotbed of support

North Waziristan is seen as a hotbed of support for the Taliban and al-Qaeda, and an army offensive has been anticipated since fighters abandoned, last month, a peace pact struck with the government in September.

There have been several clashes between Pakistani troops and fighters over the past few weeks as the army reinforced checkpoints and carried out more patrols.

Fighters have struck back with a series of attacks, including suicide bombings, in Waziristan and elsewhere in the North West Frontier Province.

More than 200 people have been killed in bomb attacks and clashes since trouble broke out at the Red Mosque in early July.

On Tuesday, Arshad announced the launch of an offensive by Pakistani security forces against hideouts that he said were being used by pro-Taliban fighters in North Waziristan.

He said forces hit targets in Daygan, a village 15km west of the town Miranshah, after receiving "credible intelligence that fighters were present there".

Cobra helicopter gunships and artillery launched the attack at about 5am (0000 GMT) and it lasted about four hours, he said.

No ground forces were used in the assault, and there was no immediate word on casualties.

Staging post

"The militants used to regroup and prepare attacks on security forces and take refuge at these compounds, so security forces targeted them," Arshad said, calling the compounds a "staging post."

A doctor in Miranshah said his hospital received three wounded people, including two children.

Witnesses there said the helicopters destroyed three houses. They also said the army was using mortars and artillery.

"As soon as firing began we ran out and during that a bomb hit our house," Attaullah Jan, one of the wounded, said from a hospital bed.

PHOTO CAPTION

Pakistani soldiers in Miranshah. Fresh violence left 23 people, including four soldiers, dead in an escalation of the bloody unrest that has rocked Pakistan over the past month. (AFP)

Al-Jazeera