Three girls, one wielding a knife, carried out a string of robberies last week on the streets of Vancouver, police said Thursday.

In each of the three robberies, the girls approached their victims, showed a kitchen knife and demanded money and personal property, Vancouver police Const. Anne Longley said.

The incidents occurred in the area of Earles Street and Vanness Avenue. in East Vancouver, Longley said.

In one case, the victim handed over her purse; in the other two, the victims refused and ran away. No one was hurt in any of the robberies.

During one incident, on April 22, the victim called 911 with a description of the robbers. As a result, two girls, ages 11 and 13, were arrested on a SkyTrain.

"The 13-year-old has been charged with robbery, and the 11-year-old was taken home as she is too young to face criminal charges," Longley said.

Longley said youth-squad investigators have been seeing younger girls involved in more violent incidents.

Police are still looking for the third suspect in the robberies.