Two policemen were killed and three others injured when an oil drilling company's plant was attacked in Pakistan's northwest Khyber Pakhtunkhwa province on Tuesday, police said, Ednews informs via Xinhua.

The incident happened in Drazanda area of Dera Ismail Khan district when 20 to 22 militants, well-equipped with sophisticated weapons, tried to enter the plant in the wee hours of the morning, Police Deputy Superintendent of Drazanda Sher Ullah told Xinhua.

Policemen at the main gate of the plant acted promptly and retreated the attack, forcing the attackers to flee, the officer added.

He said that the attacked site had an oil well and residences of staff, adding that the magnitude of the attack might have been bigger if the attackers succeeded in entering the area.

The plant has multi-layered security by police and paramilitary troops, which was on high alert following the recent surge of terrorist incidents in the country, the officer said.

The injured policemen have been shifted to a nearby hospital, the officer said, adding that the militants have fled to hilly area, and police were identifying their affiliation by evidence left by them.

No group claimed responsibility for the attack.

Security is on high alert across Pakistan following an uptick in attacks on police and security forces.