ISLAMABAD - Twenty-seven Pakistani police and paramilitary soldiers and up to 40 insurgents were killed in clashes after heavily armed militants crossed over from Afghanistan and attacked a checkpoint, officials said on Thursday.

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Skirmishes broke out after about 200 militants launched a pre-dawn attack on the post in a remote village in Dir region on Wednesday.  

"We have shifted the bodies of police and paramilitary forces killed in the clash to a hospital and now they are being transported to their hometowns," Murad Khan, a local police official, told Reuters by telephone.  

He said 35 to 40 militants were killed. There was no way to verify that toll because most journalists are not allowed to enter the border region in the northwest, the epicentre of fighting between militants and security forces.  

Militants often dispute official casualty counts.  

"They (militants) have taken away the bodies of their men," said Khan.  

Pakistan's Taliban movement, which has close ties to al-Qaida, has increased pressure on the US-backed government after vowing to avenge the killing of Osama bin Laden by US special forces on May 2 in a Pakistani town.

It has stepped up suicide bombings, attacking paramilitary cadets, a naval base, a US consulate convoy and other targets.

Government officials said army troops were moved to Dir early on Thursday to support security forces. The fighting lasted for more than 24 hours.  

"The fighting has now stopped and our forces have now regained the control of the area," a security official said.  

The battle erupted after militants dressed in military uniforms attacked the post and killed one policeman.  

After the bin Laden raid, Washington reiterated its call for Pakistan to crack down harder on militancy, especially on groups that cross over to Afghanistan to attack Western forces.

It was not clear which militants had taken on security forces in Dir, but groups along the frontier are closely linked.