At least seven people were killed and several others were injured when a mob of suspected militants attacked a major power station in northwest Pakistan, police said Tuesday.

The attackers, who numbered around 50, hurled mortars and rocket-propelled grenades at the biggest power station in Khyber Pakhtunkhwa province, disrupting the power supply to half of Peshawar city.   

"They attacked the power station at around 2:30 a.m. (21:30 GMT). They killed two officials on the spot and abducted 10 others," Javed Khan, a senior police official in the area, told the AFP.

Local official Mohammad Ishaq said that a policeman and a security guard were killed and five others died after being kidnapped in Monday's incident after being shot by the assailants, Reuters reported.

The bullet-riddled bodies of the captives were recovered later, police officials said, who added that four Water and Power Department employees and a policeman were still missing.

"They entered the grid station and started setting ablaze each and everything," Ishaq said. "They kidnapped nine people and killed five of them later and threw their bodies in the fields." 

The entire power station was destroyed in the deadly attack, which occurred in the run-up to the May 11 general elections. Following the attack, more than 100,000 people faced a power blackout in Peshawar city, for five hours.

"We later restored electricity in those areas through alternate sources," Shaukat Afzal, spokesman for the Peshawar Electricity Supply Company (PESCO) said.

No group has claimed responsibility for the attack yet. However, Pakistan’s Taliban had vowed to increase attacks ahead of the polls. The attack underscores the rising Taliban insurgency in Pakistan’s northwest region bordering Afghanistan.

Despite undertaking several counter-insurgency measures against the militants, Pakistan’s military has failed to reign in extremist groups backed by Al-Qaeda and the Taliban in the Khyber Pakhtunkhwa province, near the Afghan border.