Islamabad (PTI): At least 40 militants and four security personnel were killed in restive northwest Pakistan on Saturday as troops backed by helicopter gunships targeted hideouts of the local Taliban, which has carried out three suicide attacks in the country this week.

Security forces fought fierce battles with Taliban militants in Kabbal tehsil of Swat valley of North West Frontier Province, where an anti-militancy operation is underway.

At least 30 militants were gunned down during the clashes, Pakistani media reports quoted government sources as saying. Four security personnel were killed and 11 injured.

Several prominent militant commanders were among those killed, reports said.

Meanwhile, in nearby Bajaur tribal agency, 10 militants were killed during an ongoing operation of security forces against extremists.

Earlier today, at least 20 people were killed when a suicide bomber rammed his explosive-laden vehicle into a police station at Charbagh in Swat valley.

This was the third suicide attack in Pakistan since Tuesday when 30 people were killed in an attack in a hospital at Dera Ismail Khan town in the same province.

Seventy-eight people were killed when three suicide bombers blew themselves up outside a ordnance factory complex in Wah cantonment, about 50 km from Islamabad, on Thursday.

The Taliban has claimed responsibility for all the three attacks.