A bomb squad was at a South Carolina beach on Sunday after Hurricane Matthew apparently unearthed old Civil War cannonballs from the sand.

Charleston County Sheriff's spokesman Maj. Eric Watson said in a news release that the cannon balls were found on Folly Beach Sunday afternoon, but bomb squad members couldn't get to it immediately because of the rising tide.

Once the ocean level goes down, Watson said technicians would render the cannonballs safe. He warned residents might hear a small boom.

CCSO Bomb Team evaluating the discovery of an old civil war ordnance on Folly Beach #chsnews — ChasCoSheriff (@ChasCoSheriff) October 9, 2016

The first shots of the Civil War were fired at nearby Fort Sumter in 1861.