Four gunmen attacked the Pakistani Stock Exchange in Karachi, killing 2 guards and a policeman and wounding 7 others before being shot dead.
Early this morning, the assailants launched a grenade attack at the main gate to the building and opened fire.
The authorities say guards fought back, killing all 4 heavily armed attackers.
Three police officials are among the 7 wounded, receiving treatment in hospital.
The attackers did not manage to enter the main building and grenades, explosives and other weapons were recovered from them.
The Pakistan Stock Exchange confirmed that no militants made it into the building.
Staff inside took refuge in locked rooms and many were evacuated.
Security forces are searching the area.
Militants from the Baloch Liberation Army say they were behind the attack.