Chicago police are warning residents of a string of recent armed robberies on the North Side.

In the robberies, three armed African-American males between 19 and 25 approach people in a black SUV and demand belongings, police said. In some instances, the gunmen demanded people unlock their phones or provide their passcodes before fleeing the scene.

The robberies occurred in the: 2000 block of North Damen Avenue on July 10 around 6:25 a.m.; 3800 block of West Lawrence Avenue on July 11 around 4:55 a.m.; 5300 block of North Elston Avenue on July 11 around 5:19 a.m.; 4900 block of North Elston Avenue on July 11 around 5:04 a.m.

Police encourage residents to pay attention to people loitering in the area and ensure that surveillance cameras are functional.

Anyone with information on the robberies should call (312) 746-7394.