Police and security officials are among those confirmed dead, said Mohammad Azeem, an employee of the Edhi Rescue Center, a reputable local charity.
Rescue and paramilitary security are at the scene, Azeem said.
The video shows security and barricades off the stock market in Karachi, according to CNN’s subsidiary Geo News.
Abid Ali, the director of the Pakistani stock exchange, said in a media briefing for Geo News that four attackers joined the team and started shooting, but that he was killed by security forces.
“There were four attackers who came from the parking lot, threw a grenade at the main entrance of the KSE (stock exchange) and then started firing indiscriminately,” Ali said.
“The attackers were in a uniform that looked like a police uniform. All four were killed and the situation is currently under control.”
“We will issue more detailed statements in due course after the situation is controlled and more details are known. For now, the shooting has been stopped and the reinforcement is in force,” the tweet reads.
The administration of the Pakistani Stock Exchange sent a message saying that the “guests” had entered the compound and that the “four terrorists” were dead.
The management told the workers inside the building to stay on the higher floors and that “the rangers will comb the joint and let everything go neatly”.
The Pakistani stock exchange in Karachi is the largest in the country. It is located in the city’s financial center, where all the major banks and financial services are located and where there is usually a large security presence.
This is an evolving story.