(KRON) -- Two Bay Area police departments are warning the public about jewelry thieves with a specific M.O. According to the Fremont Police Department and the Sunnyvale Department of Public Safety, thieves have been swapping victims' jewelry with a fake piece after distracting them. Gun, ammunition, drugs found in 2 Santa Clara search warrants The robberies have been happening by the side of the road while the victim is walking. The suspect, who is often in a car, approaches the victim asking questions, offering prayers or saying it is their birthday. In some cases, the scammers asked for a hug, both police departments said. During the process, they can swap out the piece of jewelry while the victim is distracted. "After the switch, the victim may not realize the theft has occurred until it's too late, often when they examine their belongings later," Sunnyvale DPS said. Fremont PD listed the following tips to stay safe: Don't walk alone. Do not wear valuable jewelry while walking. Be mindful of who approaches you and who you talk to. Do not let strangers hug you or show strangers your valuables. Carry a cell phone with you at all times. If you are a victim, call 911 and be ready to report incident location, suspect description and vehicle description.