According to details, gangsters opened fire at the law enforcers as they raided a location in Rexer Lane area upon an intelligence tip-off.
However, three gangsters linked with Baba Ladla group were killed in retaliatory fire by the Rangers personnel.
The slain gangsters were reportedly involved in the killing of over 20 people.
Two more hardened criminals were said to be killed in another encounter which took place at Dubai Chowk, while three others were arrested.
The law enforcers also seized weapons from the arrested accused.