Police in St. Catharines busting what they call a mobile drug dealing operation.

The investigation began in June and ended yesterday with a raid on a Westchester Avenue apartment.

Police say before they entered the apartment they watched a man leaving the residence, they followed him to Eastchester and Bunting where he was arrested at a traffic stop

Police say he was carrying a quantity of crack cocaine.

At the same time police searched the apartment, and three other people were arrested inside,.

Police also seized over 6 ounces of coke and found a weapon as well.

Facing charges 23 year old Hassan Hassan, 22 year old Olivia Smith, 24 year old Ali Mahmoud and 25 year old Djamal Mahmoud.