Fireworks in a Rowan County mailbox and trash can Wednesday prompted a road closure as deputies warned residents to be cautious, according to the Rowan County Sheriff's Office.

The U.S. Postal Service and the sheriff's office are investigating fireworks being detonated in the mailbox and trash can, the sheriff's office said late Wednesday afternoon.

Earlier, deputies said the "suspicious device" was found along west N.C. Highway 152 between Stirewalt Road and Brown Road near China Grove. The area was closed off.

Residents within three miles of Five Forks and N.C. 152 should be particularly cautious, according to Rowan County Emergency Services.

The county said there have been "incidents involving small explosions in mailboxes in the area."

"The Rowan County Sheriff's Office urges the public to use caution when checking their mailbox and trash cans located by the roadside," the sheriff's office said Wednesday afternoon. 

The sheriff's office did not release any other details about the devices.