PESHAWAR (AFP) - Dozens of gunmen attacked an electricity plant in northwest Pakistan overnight, killing seven people and destroying machinery that disrupted power to many areas, officials said Tuesday.

Around 50 militants carried out the attack in Badh Bher in the suburbs of Peshawar, the capital of Khyber Pakhtunkhwa province which is rife with Al-Qaeda-linked militants and Taliban insurgents.

"They attacked the power station at around 2:30 am (2130 GMT). They killed two officials on the spot and abducted 10 others," Javed Khan, a senior police official in the area, said.

"They threw five dead bodies of the kidnapped officials in the fields close to the power house on Monday morning. Five others are still missing," Khan said.

A spokesman for the Peshawar Electricity Supply Company (PESCO) said the militants killed four of its staff and three policemen.

"One PESCO employee and one policeman were killed on the spot. The militants then kidnapped seven PESCO employees and three policemen. Later, we found the bodies of three PESCO officials and two policemen," said Shaukat Afzal.

"Four power house employees and one policeman are still missing," he said.

Violence has been increasing in the northwest as Pakistan prepares to hold general and provincial elections on May 11, which are due to mark the country's first democratic transition of power.

Pakistan says more than 35,000 people have been killed as a result of terrorism in the country since the 9/11 attacks on the United States.