The guards, affiliated with a private company, were shot at multiple times while on duty outside the Federal Board of Revenue (FBR) office in Gulistan-e-Jauhar here.
"The two security guards who belonged to a private company were posted at the FBR offices for the last 15 years," Sindh Home Minister, Anwar Sayal said.
Karachi has witnessed a rise in crimes in August with a number of bank robberies being carried out in different parts of the city.