Casualties were feared as a blast hit a government registration office in downtown area of Karachi in southern Pakistan Saturday morning, reported local Urdu TV channel Express.

According to the report, the blast took place at about 11:30 a. m.local time near an office of the National Accountability and Database Registration Authority (NADRA) in the Bahadar Abad area of the city.

Police sources said that the bomb, which contained an estimated five kg of explosives was, planted somewhere between the NADRA office and a nearby international red cross office.

No casualties have been reported yet in the blast.

Police have arrived at the blast site shortly after the blast was reported and a bomb disposal squad is searching for other possible bombs planted nearby.

Other details about the explosion are not immediately available.