Security guards at the site of the attack at the Pakistan Stock Exchange building in Karachi, Pakistan on June 29, 2020. (Photo: AFP/ VNA)

The police chief in Pakistan’s biggest city and financial hub, Ghulam Nabi Memon, told Reuters the gunmen attacked with grenades and guns after pulling up in a silver Corolla car.

They threw a grenade at security men posted outside the compound then opened fire on a security post.

The four were killed when security forces responded.

No political or religious group has claimed the attack.