Four militants were killed in a heavy firing and explosion taken place near army headquarters in Pakistan's garrison city of Rawalpindi Saturday, local TV channel reported.

According to an eyewitness, the shooting began when a carry vehicle was intercepted by army personnel at the main gate of army headquarters on Mall Road. The miscreants sitting on vehicle opened heavy indiscriminate firing on security forces. Army soldiers surrounded the vehicle and retaliated, the private TV GEO News reported.

Army spokesman major general Athar Abbas said several soldiers were shot dead in the attack while all four militants were killed.

He said that after the militants attacked the first check post, they left the vehicle, moved on and started firing on the second check post.

Abbas said that the situation has been controlled and the military was assessing its losses in the incident.

As many as five hand grenades were hurled from the vehicle, and the entire area has been cordoned off and the road has been closed for traffic.

According to sources, the militants were dressed in camouflage uniform, arms and ammunitions were present in the vehicle.

Army commandos rushed to the site and started searching operation and military helicopters are hovering over the area to monitor the situation, witnesses said.

Pakistani President Asif Ali Zardari condemned the attack at army headquarters in Rawalpindi, a city near the capital Islamabad and said in his statement that such incidents could not weaken governments' commitment against terrorism.