BALTIMORE -- Tug boats began working to dislodge a stranded container ship Tuesday, more than two weeks after it ran aground in the Chesapeake Bay.

       From shore, three tug boats could be seen pulling on taut lines attached to the rear of the Ever Forward, sending puffs of smoke into the air. Dozens of people gathered at a park nearby to watch the work Tuesday afternoon.

       The more than 1,000-foot (305-meter) ship operated by Taiwan-based Evergreen Marine Corp. was headed from the Port of Baltimore to Norfolk, Virginia, on March 13 when it ran aground north of the Chesapeake Bay Bridge, the U.S. Coast Guard said. Officials have said there were no reports of injuries, damage or pollution.

       A salvage company began dredging around the ship a week later and Evergreen said in a statement Tuesday that enough material has been displaced for the attempts to free the vessel. The plan was for five tugboats to work together in the effort and to reduce the ballast water on Ever Forward to lighten the ship, Evergreen said.

       At noon, officials extended a 500-yard (457-meter) safety zone around the ship to 1,000 yards (914 meters), closing the navigation channel to commercial traffic until midnight.

       If the ship is not refloated Tuesday, dredging will start again and a second attempt will be made Sunday, officials said. If both attempts at freeing the ship are unsuccessful, the removal of containers will have to begin, according to a marine safety information bulletin.

       The Coast Guard has said they have not yet determined what caused the Ever Forward to run aground. The ship ran aground outside the shipping channel and has not been blocking navigation, unlike last year’s high-profile grounding in the Suez Canal of its sister vessel, the Ever Given, which disrupted the global supply chain for days.