Two teens and a Bowie man have been charged in connection with armed robberies that Prince George’s County police say targeted victims through Craigslist and other online classified ad services.

Four victims either trying to buy or sell phones through Craigslist or an app called “OfferUp” were robbed in broad daylight over a six-day period this month, police said in a statement announcing the arrests Thursday. In three cases, victims reported being robbed at gunpoint, police said.

Police said they arrested Alford C. Wade III, 26, in a robbery June 10 on Martin Luther King Jr. Highway in Bowie. In that incident, police said, a man reported that his cellphone was taken.

Kemith E. Calvin, 17, was arrested in a June 12 robbery of a man who was reportedly selling a cellphone in the 800 block of Congressional Court in Bowie, authorities said. Detectives charged Calvin as an adult, police said.

Police recovered a gun Calvin’s case and a replica of a gun in Wade’s case, authorities said.

Alford Charles Wade (Courtesy of Prince George's County Police)

Police also charged a 15-year-old in another reported robbery, but did not name the teen. He said the teen arrested was also charged with phone theft two years ago.

At a news conference Friday, Lt. Sunny Mrotek said the police department wasn’t discouraging anyone from using online classified services, but he warned the community to exercise common sense and caution.

Mrotek said in the past, these types of crimes involving online classified in the county were isolated incidents. But at least two of the cases this month were connected. Mrotek said police are still looking for at least three other persons of interest in the cases.

Kemith Eugene Calvin (Courtesy of Prince George's County Police)

Mroteck suggested that anyone using online classified services bring another person with them to a transaction in a public place, and avoid bringing buyers to their homes whenever possible. He also suggested users talk to people on the phone to settle the details of a transaction before meeting.