Calgary Police are investigating a string of cellphone robberies.

Over eighty thefts occurred in retail stores across the city between February 23 and March 15, 2018.

In the most recent incidents, suspects used force to confine the staff within the targeted stores, before fleeing.

Police believe all of the cases are connected and are asking for help finding more suspects.

Four young offenders between the ages of 16 and 17 have been charged in connection with one of the thefts.

Investigators are asking anyone with information about these incidents or the identities of the people involved to contact police or Crime Stoppers.