Heavy firing was reported at the Airport Security Force (ASF) camp number 2, situated near the Jinnah International Airport, Dawn News reported.
About four to five terrorists attacked the camp from Pehlwan Goth side, TV channels reported.
Exchange of firing continues between the ASF officials and terrorists outside the camp. Sounds of explosions were also heard, causing panic among citizens in the vicinity.
Ranges and police continents have rushed to the scene.
An emergency situation has been imposed in the area.
The attack came a day after the deadly assault at Karachi international airport in which 12 security personnel, 8 civilian and 10 terrorists were killed.
The outlawed Tehreek-e-Taliban Pakistan (TTP) has claimed responsibility for the attack on airport.