Dozens of gunmen attacked an electricity plant in northwest Pakistan, killing seven people and disrupting power to 100,000 people overnight, officials said Tuesday. It was the latest audacious assault underscoring rising violence 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. Around 50 militants targeted the plant in Badh Bher a suburb of Peshawar, a key electoral battleground and 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, told AFP. "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." There was no immediate claim of responsibility for the attack. A spokesman for the Peshawar Electricity Supply Company (PESCO) said four of its staff and three policemen were killed. "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." The attack shut down electricity for five hours, affecting around 100,000 people in surrounding areas, the spokesman said. "We later restored electricity in those areas through alternate sources," Afzal said. There are fears that rampant insecurity could prove a major challenge for the vote, not least in Peshawar, home to 2.5 million on the edge of the tribal belt on the Afghan border, Pakistan's premier Taliban and Al-Qaeda stronghold. The Tirah Valley has offered Pakistan's umbrella Tehreek-e-Taliban (TTP) a new base in the tribal district of Khyber, beyond the reach of ground troops and posing a heightened threat to Peshawar. On Sunday, a bomb attack near an election rally killed two people and injured six, including a candidate in the northwestern town of Bannu. TTP claimed responsibility for the bombing and threatened more attacks against the ANP, the secular Awami National Party that headed the outgoing government in Khyber Pakhtunkhwa. The Pakistani Taliban have threatened the main secular parties who backed army operations against the Islamist militants. 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.