Chicago police are investigating at least four armed robberies that occurred within 40 minutes of each other on the North Side Sunday night.

       Police said detectives haven’t yet established a pattern or connection between the robberies, all of which involved three to four men and a white SUV. No suspects are in custody, and police said they are investigating.

       The first robbery happened at about 11 p.m. in Lincoln Park. Four men got out of a white SUV and took a 42-year-old woman’s purse at gunpoint when she was walking on the sidewalk in the 900 block of West Armitage Avenue, according to police, who added that the woman wasn’t injured.