An explosion was reported aboard a cargo ship in Baltimore's harbor Monday, near the site of the Francis Scott Key Bridge collapse, U.S. Coast Guard officials said. No injuries were reported.

Authorities are investigating the cause of an explosion aboard a cargo ship that was leaving the Port of Baltimore when it issued a mayday call.

The main channel used by cargo ships to enter and exit the Port of Baltimore was closed off Tuesday as the Coast Guard sought to probe the cause of a Monday evening explosion on board a coal