Rescuers have a 12-24 hour window to complete a search for survivors in the wreck of an Italian cruise liner capsized off a Tuscan island, the head of a firefighters' diving team said on Thursday.

There is a 12-24 hour window to complete the operations, Modesto Dilda told Reuters.

Eleven people are confirmed dead and about 20 are still missing from more than 4,200 passengers and crew who were onboard when the vessel foundered on Friday evening, two hours into a week-long cruise of the western Mediterranean.

(Reporting by Steve Scherer; Editing by Mark Heinrich)