A stricken Italian cruise liner shifted on its rocky resting place on Monday as worsening weather disrupted an increasingly despairing hunt for survivors and authorities raised their estimate of the number missing to 29 people.

As the Costa Concordia's owners blamed their captain for veering shorewards on Friday in a bravura salute to residents of a Tuscan island, the giant ship slid a little, threatening to plunge its whole gigantic carcass and 2,300 tonnes of fuel below the Mediterranean waters of the surrounding nature reserve.