DISCOVERY BAY -- Four teenagers escaped serious injury after being attacked in three robberies during a 24-hour period by possibly the same group of juveniles, an investigator said.

A 19-year-old pizza delivery driver, two 14-year-old boys and a 13-year-old boy were beaten up in the robberies, which all are thought to have been committed by juveniles, Contra Costa sheriff's Lt. Mike Burton said. None of the teens were hospitalized, sheriff's spokesman Jimmy Lee said.

"We are giving the investigation of these robberies a high priority," said Burton, adding that violent crimes in Discovery Bay are rare.

The man delivering pizzas was attacked about 9 p.m. Monday in the 1400 block of Cullen Drive and robbed of cash, an iPod, several pizzas and a soda.

One 14-year-old boy was attacked about 5:30 p.m. Tuesday while walking along Lakeshore Circle, losing his headphones. A little more than an hour later on the same street, a 14-year-old and 13-year-old were attacked, and one of the boys was stripped of an iPod.

Sheriff's deputies searched the areas, using dogs after the initial robbery, but were unsuccessful and are asking for the public's help. The Sheriff's Office asks anyone with information on the robberies to call the department at 925-646-2441 or Burton at 925-427-8510.

Contact Rick Hurd at 925-945-4780.