Harmony of the Seas, the world's largest cruise ship, has begun its first sea trial in western France.

Thousands of people gathered to watch in the port of Saint-Nazaire as the 70m (230ft) high vessel was guided out to sea by six tugs on Thursday March 10, according to BBC News.

The €1bn ($1.1bn) ship is being built for the Royal Caribbean International (RCI) cruise company. The 120,000-tonne vessel is expected to be delivered to the U.S.-based firm in two months. The trial will continue until Sunday.

The 16-deck Harmony of the Seas is 362m long - 50m longer than the Eiffel Tower is high. After completion, it will be able to accommodate more than 6,000 passengers.

About 2,000 crew members will cater for their needs.