Update: On Saturday morning, news images showed the vessel on its starboard side, with a large gash visible on the port side of the hull underside, at about midships.
In an earlier statement, Costa said the evacuation began promptly but ‘the position of the ship has worsened, making it more complicated to complete the last part of the evacuation.’
It added: 'In this moment all our efforts are focused on the completion of the last emergency operations, besides providing assistance to the guests and crew who were on board in order to have them going back home as soon as possible.'
According to the BBC, passengers were eating dinner when they heard a loud noise and the lights went out. Passengers and crew were sent to the lifeboats. News reports said a few people had jumped to swim ashore.
Costa could not immediately confirm what caused the accident but pledged to fully cooperate with authorities. The line acknowledged the assistance of the Italian coast guard for coordinating rescue efforts and thanked the authorities and citizens of Giglio who are providing assistance.
Costa said about 1,000 Italians, more than 500 Germans and 160 French were among those on board, along with approximately 1,000 crew.
The cruise had sailed from Civitavecchia.
Built in 2006, the 120,000gt Costa Concordia has capacity for 3,800 passengers.