Hamilton police are investigating after a string of violent street robberies on Hamilton Mountain.

The first incident happened around 10 p.m. Tuesday at park on West 5th St.

Police say four or five men approached a man who was in the park, assaulted him and stole his wallet and cell phone. The group then took off in a vehicle.

About ten minutes later, a group of men entered the parking lot of the Columbia International College residence on Sanatorium Rd. Two men got out of the vehicle, assaulted and robbed two victims. The thieves got back into their vehicle and sped off.

The third robbery happened about an hour later at McQuesten Park on Upper Wentworth St. Police say a man was attacked at knifepoint by four or five men who stole his money as well as some of his clothing.

Investigators believe the same group of men are responsible for all three incidents and are asking anyone with information about the crimes to contact Hamilton police.