Over 100 militants launched an attack late Friday night on a checkpost in the Sarband area of Peshawar, a major city in northwestern Pakistan, a source in Peshawar told Xinhua on telephone.

According to the source who is a local journalist in Peshawar but declined to be named, an estimated 120 militants attacked a checkpost located some 30 kilometers southwest of downtown Peshawar at about 11:00 p.m. local time.

Some local media reports said only 50 militants were involved in the attack. The exchange of fire between the militants and police is still going on there, said the reports, adding more police have been called in to reinforce the checkpost under the attack.

Details about the militants and casualties are not immediately available at this point.

As the checkpost is located near the tribal area of Khyber Agency which borders Afghanistan, it often falls under attack by militants, said the local media reports.