COSTA MESA (CBSLA) — Investigators believe armed robberies in four Orange County cities were all committed by the same person, authorities said Monday.

Police in Costa Mesa, Huntington Beach, Tustin and Irvine are working together to try to find a man detectives believe went on a crime spree Sunday night. The robberies happened at restaurants and gas stations, and all involved a gun being taken out before the robber demands money, then takes off.

The first robbery happened about 7:40 p.m. at a Chevron gas station at Jeffrey Road and Alton Parkway in Irvine. Less than an hour later, a hold-up was reported at a McDonald’s on Bryan Avenue in Tustin, after a man ordered food, then took out the gun when the register was opened.

At a Carl’s Jr. on Magnolia and Adams in Huntington Beach, a man ordered a milkshake at about 10 p.m., then pulled out a gun as soon as the register drawer opened. He got away with about $40. About a half hour later, an Arco gas station on Gisler and Harbor Boulevard in Costa Mesa was robbed in similar fashion.

Huntington Beach police say the description of the gunman in their robbery matched very closely with the incidents in Costa Mesa, Tustin and Irvine. Detectives are now working to confirm whether the robberies are indeed connected, and gathering evidence at each scene.

No injuries were reported from any of the four robberies.