While the day after Thanksgiving is the unofficial start of the holiday shopping season for bargain hunters, for law enforcement, it's also the start of the vehicle-burglary season.

"We definitely see an increase in vehicle burglaries," said Redlands police Sgt. Jeremy Floyd. "Usually people leave their packages in plain sight or their vehicle unlocked."

Since it's only the beginning of the holiday shopping season, hard numbers on any increase are not yet available, but most law enforcement agencies agree they see an uptick in the crime between Thanksgiving and Christmas.

"The reason for that is there are more people out shopping," said San Bernardino police Lt. Dario Robinson. "This is a crime of opportunity so the more people are out there, the more chance there is to be victimized if people aren't mindful."

Authorities advise shoppers to take precautions by following some common-sense tips, including making sure their vehicles are locked and not leaving packages in plain sight.

Robinson advises shoppers not leave packages in their vehicles at all.

"These guys are watching shoppers and if they see you put your bags in the trunk, they wait for you to go back to shopping and then break into the trunk," Robinson said.

He suggests shoppers take their packages home.

Some holiday Grinches not only strike in the parking lots of shopping centers, but also in the stores themselves.

"When you go shopping, don't let anyone see how many credit cards or how much cash you have in your wallet," Robinson advised.

He suggests people take only one credit or debit card so if it becomes lost or stolen, no one will have access to multiple accounts.

Creating a special account where only a limited amount of money is kept specifically for holiday or online shopping is also a good idea, Robinson said.

"If someone does get a hold of your information (online) or card, then you only lose what's in that account and you don't get cleaned out," Robinson said.

One of the most important tips for shoppers is always be aware of their surroundings.

"If you notice someone following you, call us," said Floyd. "It's not going to hurt for us to go out and investigate because chances are if it looks funny to you then there may be a reason for concern."