Winnipeg police are reminding people to exercise caution when buying and selling online after a string of violent robberies Tuesday evening.

The first incident happened around 5:30 p.m., when an 18-year-old man tried to sell clothing he had posted online. Police said he met two suspects at an arena in the Valley Gardens area and was robbed after one suspect pulled out what was described as a firearm.

The second robbery happened around 5:50 p.m. when police said suspects met an 18-year-old who was trying to sell shoes online in the St. Vital area, later physically assaulting and robbing him.

Police said a 25-year-old was then assaulted in the Exchange District while trying to sell a watch he had advertised online. A suspect allegedly pulled what police believe was a BB air pistol, put it to the 25-year-old’s head and fired several shots. He was later able to run away and was transported to hospital, but Const. Jay Murray with the Winnipeg Police Service described his experience as potentially “traumatic.”

“He’ll require lasting treatments. It isn’t something he’s going to walk away from quickly,” said Murray.

“You look at the lasting psychological impact that might take place on this person, who essentially had what they thought was a firearm pointed against their head and the trigger pulled. I don’t want to speculate too much, but it’s very disturbing.”

Police told media at roughly 7:15 p.m., a 27-year-old man was hit in the head multiple times with a weapon and then robbed.

Officers caught up with the suspects around 7:55 p.m. according to police, and made an arrest after officers spotted a suspect vehicle in the area of Lagimodiere Boulevard and Grassie Boulevard. Police said a BB air pistol was seized from within the vehicle.

Two 17-year-olds are facing a number of charges including armed robbery using a firearm and aggravated assault.