CHICAGO (CBS) -- Police are looking for armed carjackers who stole three cars in less than 48 hours in the Park Manor neighborhood.

Chicago Police said a group of two or three carjackers approached the victims as they were standing outside their vehicle, and demanded their vehicles at gunpoint.

The incidents happened:

• around 1 a.m. on Aug. 30 in the 7100 block of South King Drive;
• around 6 p.m. on Aug. 30 in the 7400 block of South Wabash Avenue;
• and around 9:15 p.m. on Aug. 31 in the 7300 block of South Champlain Avenue.

Police had only a vague description of the suspects, who were wearing hoodies and masks.

Police cautioned drivers to always be aware of their surroundings, and to remain calm if confronted by a carjacker, and try to remember any unique physical characteristics of the attacker or attackers.

Anyone with information on the carjackings is asked to call Area One detectives at 312-747-8384.