Two people were injured during a California tall ship festival when a shotgun shell was loaded into a ship's cannon and fired at another vessel during a mock battle.
The Orange County Register said authorities were investigating how a shotgun shell containing pellets was fired instead of a blank, plain powder charge.
Authorities said the Amazing Grace, a tall ship based in Washington state, fired at the vessel Bill of Rights on Saturday, hitting two people on board during a Dana Point festival that celebrates 19th-century seafaring. The injuries were said to be minor.
Both ships were using small cannons that use blank charges that look like common shotgun shells.
Orange County sheriff's spokeswoman Gail Krause said her department was awaiting the outcome of the investigation before deciding whether to pursue charges of negligent discharge.