Four containers at a shipping terminal in South Carolina were examined and cleared after a false threat of a "dirty bomb," Pentagon officials said Thursday.

The FBI said late Wednesday it was investigating the claim on the Maersk Memphis ship at the Wando Terminal in the Port of Charleston.

The terminal was evacuated, along with a section of the Cooper River. Authorities said Thursday the terminal would re-open and the safety zone was lifted.

Capt. Greg Stump, the commander for the Coast Guard sector in Charleston, said a YouTube “conspiracy theorist” made a clam about a threat on board one of the ships, according to WCIV.

Workers told Fox Carolina they were all sent home and told to leave the terminal at around 9 p.m.

Boaters were also escorted off the water due to the situation, according to the station.

Fox News' Jennifer Griffin contributed to this report.