Rome, Italy (CNN) -- The bodies of five more people killed when the Costa Concordia cruise ship sank were found Thursday, bringing to 30 the number of bodies located, Italian officials said.
Two of the roughly 4,200 originally aboard the cruise liner remain missing. The Costa Concordia, a ship belonging to cruise line Costa Crociere, struck rocks off the island of Giglio on January 13 with about 3,200 passengers and 1,000 crew members on board.
Workers completed the removal of 2,400 tons of oil from the ship's tanks this week, a delicate process that began five weeks ago, the ship's owner said Thursday.
A salvage company will be selected next month to move the ship, a task that could take a year, according to the statement from Costa Crociere.
Divers who located the three bodies Thursday were not able to immediately determine age or sex of the victims, according to Piero De Milito, an official with Italy's Civil Protection Coordination department.
"The bodies were found on the exterior side of the wreck facing the island, between the wreck and the rocks," De Milito said. "In the next 48 hours, we'll be able to bring them on the mainland."
Crews used 20 vessels, including platforms, tugs, transport ships, crane barges and tankers, to defuel the cruise ship, which remains on its side.
While the oil has been removed, the "caretaking" operation to clean the seabed and monitor the ship will continue for several months, the company said.
The cruise line will choose next month which of six bidding salvage companies will remove the wrecked ship.
"The operation to remove the wreck will be a particularly complex one and is expected to take from 10 to 12 months, depending on which tender is chosen," the company said.
Journalist Livia Borghese in Rome contributed to this report.