Gunmen have attacked the stock exchange in the Pakistani city of Karachi, killing at least three people — two guards and a policeman, according to police.
Special police forces deployed to the scene of the attack and in a swift operation secured the building, killing all four gunmen.
The attackers were armed with grenades and automatic rifles, police said.
They launched the attack by opening fire at the entrance of the Pakistan Stock Exchange in the southern port city, the country's financial centre.
Rizwan Ahmend, a police official at the scene, said that after opening fire, the gunmen entered the high walled stock exchange grounds.
He said the food supplies were found on the bodies of the gunmen, indicating they may have planned a long siege, which police quickly thwarted.
Inside the stock exchange, broker Yaqub Memon told The Associated Press that he and others were huddled inside their offices while the attack was under way.
Heavily armed special forces quickly have surrounded the building located in the heart of the city's financial district, where the Pakistan State Bank is located as well as the headquarters of several national and international financial institutions.
Local television stations were broadcasting images of police in full body armour surrounding the building but still staying outside the high walled compound of the stock exchange.
Shazia Jehan, a police spokesman, said the bomb disposal squad was also called to the stock exchange and was trying to clear the building of explosive devises.
There were no other details and no militant group immediately claimed responsibility for the attack.
The Karachi stock exchange is Pakistan's largest and oldest stock exchange, incorporated today with the exchanges in Islamabad and Lahore.