Islamabad, Sep 9 (IANS): Four people, including three suicide bombers and one policeman, were killed Monday in an attack on police headquarters in northwestern Pakistan, Xinhua reported citing local media.

Three militants attacked the police headquarters in Pakistan's northwestern district of Kohat throwing hand grenades and opening fire.

Police retaliated with intensive firing and killed all the three attackers who were trying to enter the building where dozens of policemen and civilians were present.

One policeman was among the eight people injured in the attack

The militants had automatic guns and hand grenades, with two of them wearing explosives-laden jackets.

A bomb disposal squad defused two suicide jackets while nine hand grenades were recovered from the militants.

Security forces cordoned off the area and launched a search operation for accomplices of the attackers.

No group or militant organisation has claimed responsibility for the attack yet.

Earlier in the morning, some armed people attacked a police checkpost in the southern district of Kashmore and killed three police personnel.

The incidents took place on a day when representatives of the country's major political and religious parties were having an in-camera meeting with Prime Minister Nawaz Sharif to devise a national strategy to deal with terrorism, extremism and militancy in the country.