Ottawa police are seeking the public’s help as they investigate another armed robbery during a Facebook Marketplace sale, the second such incident in the last four days.

Police say the robbery occurred Sunday evening around Berrigan and Beatrice drives in Barrhaven when a suspect pulled out a handgun and took an item from the victim after they’d arranged a sale online.

Anyone with video footage from the area taken between 7:30 and 8 p.m. is asked to contact the Ottawa Police Service’s robbery unit.

Fifteen hours later and seven kilometres away, a similar robbery took place in Manotick.

Investigators say in that case, the seller had arranged to meet a potential buyer through Facebook Marketplace, but the male suspect pointed a firearm and tried to rob them.

Two shots were fired but no one was struck by gunfire, police said. They said three people including the seller, a security guard and an off-duty police officer took the suspect into custody.

The suspect, whom police said has since been identified as a young offender, sustained minor injuries.

Ottawa police said Wednesday both robberies are under investigation and they couldn’t comment on any connections.

Ottawa police recommend buyers and sellers take advantage of safe trade zones, video-monitored areas outside several police stations across the city.

Buyers and sellers should also record any information about who they’re meeting because suspects often block victims after stealing from them, police said.