Pakistan Stock Exchange terror attack: Two security guards and policeman killed as gunmen open fire in Karachi

Four gunmen have attacked the Pakistan Stock Exchange in the southern port city of Karachi, police said.

Two security guards and a policeman were killed in the terror attack, police said.

The gunmen, who attacked the building with grenades and guns, have also been killed.

"Four attackers have been killed, they had come in a silver Corolla car," Karachi police chief Ghulam Nabi Memon told Reuters.

Rizwan Ahmend, a police official at the scene, said that after the attack was over, food supplies were found on the bodies of the gunmen, indicating they may have planned a long siege, which police quickly thwarted.

Separatist insurgents from Balochistan province — the Baloch Liberation Army — later claimed responsibility in a post on Twitter set up shortly before the raid.

Separatists have been fighting for years in Balochistan, complaining the south-western province’s gas and mineral wealth is unfairly exploited by Pakistan’s richer, more powerful provinces.

The gunmen initially threw a grenade then opened fire on a security post outside the building, which is in a high security zone that also houses the head offices of many private banks.

The four were killed when security forces posted there responded.

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.

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.

A counter-terrorism official told Reuters the attackers were carrying significant quantities of ammunition and grenades in backpacks.