Police are warning pedestrians about three robberies reported Friday in the Gold Coast neighborhood on the Near North Side.

A woman and between one and four men have been sneaking up behind people and grabbing their cell phones and purses from their hands, according to a community alert from Chicago police.

If the victim tried to stop the robbers, one of them would pull out a blue semi-automatic handgun and threaten to shoot, police said.

The robbers usually run away, but once they fled in a silver Ford Escape, police said.

The suspects were described as two to five black adults between 20 and 22 years of age, police said. One was a woman, while the rest were men.

The incidents occurred:

early March 1 in the first block of East Chestnut Street;

during the afternoon March 1 in the 900 block of North State Street;

during the afternoon March 1 in the first block of East Oak Street.

Anyone with information on the robberies is asked to call Area Central detectives at (312) 747-8380.