group of militants armed with grenades and automatic rifles laid siege to the Pakistan Stock Exchange on Monday, killing at least three people before being taken out by special police forces.

The attack on the building located in the heart of Karachi's financial district, where the Pakistan State Bank is located as well as the headquarters of several national and international financial institutions, left two guards and a police officer dead, officials say. A third guard is reported to be in critical condition.

Rizwan Ahmend, a police official at the scene, told the Associated Press that after opening fire at an entrance gate, the four gunmen entered the stock exchange grounds. He said that after the attack was over, food supplies were found on the bodies of the gunmen, indicating they may have planned a long operation.

Security personnel surrounds the Stock Exchange Building after an attack in Karachi, Pakistan, on Monday. (AP)

Security personnel surrounds the Stock Exchange Building after an attack in Karachi, Pakistan, on Monday. (AP)

PAKISTAN’S PRIME MINISTER SAYS US ‘MARTYRED’ USAMA BIN LADEN 

The Baluchistan Liberation Army later claimed responsibility for the attack. The group has been waging an insurgency for years, demanding independence for Pakistan's gas-rich southwestern Baluchistan province, which borders the southern Sindh province, where Karachi is the provincial capital.

Inside the stock exchange, broker Yaqub Memon told the Associated Press that he and others huddled inside their offices while the attack was underway. As the firing ended and the gunmen were killed, police gathered all the employees and brokers in a single room while security forces went floor by floor to ensure that no explosives had been left behind, he added.

Shazia Jehan, a police spokesman, said the bomb disposal team was also called to the stock exchange to clear the building of any explosive devices.

Security personnel examine confiscated ammunition from attackers outside the Stock Exchange Building. (AP)

Security personnel examine confiscated ammunition from attackers outside the Stock Exchange Building. (AP)

PAKISTAN ACCUSES 150 PILOTS OF CHEATING TO OBTAIN LICENSES 

At a news conference later Monday, Maj. Gen Omar Ahmed Bokhari -- who oversees the paramilitary Rangers force which took part in the operation -- accused neighboring India of aiding the attackers by allegedly activating “sleeper cells” that Pakistan claims Indian intelligence has planted throughout the country.

India and Pakistan routinely exchange allegations of using militant groups to attack the other country. The two nuclear-armed neighbors have fought three wars, two of them over the disputed Himalayan mountain region of Kashmir, which is divided between the two but coveted by both in its entirety.

The Baluchistan Liberation Army, which Pakistan says has found safety across the border in Afghanistan, has carried out several attacks in Karachi in recent years, including an attack on the Chinese Consulate in November 2018 that killed two people.

Security personnel check a car used by the attackers. (AP)

Security personnel check a car used by the attackers. (AP)

Gen. Bukhari said Monday's attack bore the same hallmarks as the Chinese Consulate attack, with the level of coordination and a large ammunition stockpile found at the scene.

CLICK HERE TO GET THE FOX NEWS APP 

Pakistani police and Rangers discovered more than a dozen hand grenades, boxes of ammunition, and several automatic rifles that the attackers had brought to the stock exchange.

The Karachi stock exchange is Pakistan’s largest and oldest stock exchange, incorporated today with the exchanges in Islamabad and Lahore.

The Associated Press contributed to this report.