A device similar to a pipe bomb exploded in a trash can at a remote Walt Disney World parking lot early Monday, authorities said. No one was injured and no serious damage was reported in what officials believe was an isolated incident.

An employee heard a loud noise and saw white smoke coming from the can near the Downtown Disney shopping and entertainment district, Orange County Sheriff Kevin Beary said.

"We have recovered a very crude, homemade, low-level device," Beary said. "Because of the time and location of the event, we do not believe this incident was designed to cause significant property damage or injury. We also believe this is an isolated incident."

Beary said investigators were still trying to determine what the device was made of, but "end caps" typical of pipe bombs were found at the scene. Beary said it blew holes in the can and blasted off its doors.

Beary said federal authorities also have looked into the incident.

Beary said authorities were on high alert because of the airport attack in Scotland and attempted car bombings in London, combined with the July Fourth holiday this week.