The ship that slammed into the Francis Scott Key Bridge in Baltimore was re-floated on Monday after being stuck for nearly eight weeks.

The Dali was “moved by tugboats under favourable environmental conditions,” according to the US Army Corps of Engineers.

Moving the ship is the latest step in clearing key shipping routes.

The Dali crashed on 26 March, causing the bridge to collapse and killing six construction workers.

The ship lost power before veering off course and striking the bridge. The collision sent around 4,000 tonnes of debris into the Patapsco River and trapped the boat. An investigation into the incident is ongoing.

The 948ft (289m) ship had remained at the scene and was covered in scrap metal from the bridge, until a controlled demolition last week cleared some of the debris.

The Army Corps of Engineers said that it would take around 21 hours to move the Dali to a nearby terminal.

A total of 21 crew members, most of them Indian, have been left on board the ship. Their phones have been confiscated by the FBI and they have had limited communication with shore. Union officials said earlier this month that “morale has understandably dipped” on board the ship.

The FBI and the National Transportation Safety Board (NTSB) are investigating the collapse.

The city of Baltimore has sued the ship’s owners, Grace Ocean Private Limited, and its manager, Synergy Marine Private Limited, alleging gross negligence and recklessness. The companies have asked a court to limit their liability for the incident.

Authorities in the state of Maryland estimate it will cost up to $1.9bn (£1.5bn) and take more than four years to rebuild the bridge.