SACRAMENTO, Calif. -- Sacramento police are looking for a man responsible for at least four recent serial stabbings, officials said.

The stabbings all appear to be random and have taken place near Del Paso Boulevard between Arden Way and El Camino Avenue, officials said.

The man has never said anything or attempted to rob his victims, officials said, and in each assault he has been riding a bicycle while his victims have been on foot.

Each victim was stabbed once in the upper body, officials said.

Police said the man is Hispanic, about 22 to 28 years old, about 5 feet 7 inches to 5 feet 10 inches tall and weighs 170 pounds.

The man's bike has been described by police as a 10-speed or mountain bike that is possibly red, gray or tan.

The knife involved in the stabbings is about 6 inches in length, with a black handle and may be a Swiss Army knife, officials said.

Anyone with information on this case can call Crime Alert at 916-443-HELP. Callers can remain anonymous and may be eligible for a reward up to $1,000.