Police are warning residents about a series of vehicle thefts reported in the last week in River North.

In two of the five incidents, the suspects stole unlocked vehicles with the keys inside, according to a community alert from Chicago Police. In one incident they took a vehicle that was left running and unattended. In two other incidents the vehicles were legally parked when they were stolen.

The thefts occurred:

At 9:30 p.m. March 27 in the first block of West Grand;

In the early morning hours of March 28 in the 500 block of North Michigan;

At 8:45 p.m. March 28 in the 400 block of East Ohio;

At 12:30 a.m. April 2 in the 100 block of East Huron; and

At 2:10 a.m. April 2 in the 300 block of East North Water.

The suspects were described as a group of four men about 20-25 years old, police said.

Anyone with information about the thefts is asked to call Area Central detectives at (312) 747-8382.