HARRISBURG — Authorities say thieves are increasingly targeting tractor-trailers in Pennsylvania to steal their loads of electronics, food or drink, later abandoning the trailers at the side of the road.

Sometimes the culprits steal trucks left idling at rest stops, or they try to find a way past warehouse security systems to take trucks during the night. On Jan. 8, for example, a tractor-trailer loaded with Coca-Cola products was stolen from a warehouse in Lemoyne, and the empty trailer turned up the next day in New Jersey.

"It was loaded and ready to go for a morning driver to come into work," said Michael Hope, the chief of the West Shore Regional Police. "When they came in, the truck was gone. It appears they just want the cargo."

Freight Watch International says cargo thefts have steadily increased since 2007. A total of 859 thefts were reported in 2009, and Pennsylvania was the eighth most-targeted state.

Walt Fountain, director of enterprise security for the Green Bay, Wisc.-based Schneider National trucking firm, said thieves are increasingly targeting trucks along Interstates 76, 81 and 83 in Pennsylvania. Over the last year and a half, they have also trained their sights on distribution centers, he said.

Thieves tend to migrate to places where law enforcement and the industry's best practices haven't caught on, he said.

Fountain described the thieves as organized crews often numbering eight to 10 people with specialized jobs that monitor targets to gauge security gaps. Such thefts were common in Florida and Georgia several years ago and then moved to Dallas after police cracked down. Since then, they have moved north through Indiana, Kentucky and Ohio and now into Pennsylvania.