The raid was carried out by Sindh Rangers in the city's impoverished Golimar area against the insurgents linked to the banned Baloch Liberation Army (BLA), officials said.
According to Sindh Rangers, the insurgents resorted to indiscriminate firing during the operation, which the paramilitary forces retaliated.
Four insurgents died in the crossfire, the Dawn reported.
An official statement said the criminals were involved in anti-state activities with the BLA.
They were involved in extortion, kidnapping for ransom and were allegedly behind a number of targeted killings.
The banned BLA dominates the resource-rich Balochistan province, the largest of Pakistan's four provinces.
But Balochistan's roughly seven million inhabitants complain they do not receive a fair share of its gas and mineral wealth, building resentment among them.
Law enforcement agencies have been actively seeking to rid Karachi - Pakistan's commercial hub - of terror and violence through operations in the city's troubled areas for well over a year now.
Both police and Rangers have raided many areas and have arrested thousands of suspects and criminals to ensure peace in the city, which has been hit by a wave of law and order problems.
