Police in Daytona Beach, Fla., issued a warning Friday for the 500,000 people expected at this year's annual Bike Week celebration to avoid getting into cars with strangers as the investigators try to determine if a serial killer is loose in the area.

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IMAGES: Victim Photos

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The large crowds began arriving in Daytona Beach for Bike Week early Friday.

However, this year, authorities are not only concerned about the crowds of bikers but also the killer or killers responsible for the slayings of three women.

The city's most recent homicide was 35-year-old Iwana Patton from Holly Hill, whose body was found in some woods near Williamson Boulevard and Mason Avenue.

Julie Green and Laquetta Gunther were killed in December.

Police are not sure if one person is responsible for the homicides or if there are three killers at large in Daytona Beach.

If one person is responsible, the FBI classifies him as a serial killer, Local 6 reporter Tarik Minor said.

"Still, police issued a warning this morning," Minor said.

"Don't get into cars with people who you don't know or know very little about," Daytona Beach police Capt. Brian Skipper said. "Just use common sense when you are out there on the streets. We are not prepared to say there is any sort of widespread public danger here."

FBI agents joined in the investigation earlier in the week.

Authorities are still searching for a mysterious caller who led them to the latest victim but refused to give any other information.

All of the homicides were committed on Friday nights.

The Florida Department of Law Enforcement is also involved in the investigation.

If you have any information concerning these crimes, you are urged to call Crimeline at (800) 423-TIPS.

Watch Local 6 News for more on this story.