Four heavily armed militants attacked the busy Pakistan Stock Exchange building here with guns and grenades on Monday morning, killing four security guards and a police officer before being shot dead in an exchange of fire.

The militants, who arrived in a car, opened indiscriminate fire and lobbed grenades at the main gate of the building. Armed with automatic machine guns and explosives, they tried to enter into the compound, which leads to the building, through a parking lot but forces foiled their attack within the compound itself, Deputy Superintendent of Police (South), Jamil Ahmed said.