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The threat came in Wednesday night

It was based on an anonymous claim shared by a man on YouTube

CNN  — 

A South Carolina port terminal was briefly evacuated because of a “potential threat” in a container ship, then reopened early Thursday after authorities scanned it and cleared it.

Authorities got a warning Wednesday night of a threat in a container on a ship at the Port of Charleston, the Coast Guard said.

The ship, Maersk Memphis, was at the Wando terminal, the Coast Guard said in a statement.

The terminal, which is used for container cargo, was evacuated to allow federal, state and local bomb detection units to conduct investigations. Authorities did not detail the nature of the threat.

When the threat was ongoing, the Coast Guard tweeted that a “safety zone has been established around the vessel” as multiple agencies investigate. Several hours later, it gave the all-clear.

“Unified Command determines no existing threat to the port. Terminal will reopen & safety zone has been lifted,” the Coast Guard tweeted. “There were four containers where threat was posed at terminal in Charleston, SC. These have been scanned and cleared by authorities.”

It said the source of the “original reporting source of the threat” has been detained for questioning.

Coast Guard Lt. JB Zorn said the threat was based on an anonymous claim shared by a man on YouTube.

The Maersk Memphis left New York three days ago, according to the MarineTraffic website.