GIGLIO, Italy - Rescue squads used controlled explosions on Tuesday to enter a stricken Italian cruise liner in the increasingly despairing hunt for survivors as authorities almost doubled their estimate of the number missing on the huge vessel to 29 people. 

The Costa Concordia's owners accused their captain of causing Friday's disaster by veering the ship too close to shore, where it hit a rock, in a bravura "salute" to residents of a Tuscan Island off Italy's Mediterranean coast.

Captain Francesco Schettino was arrested on Saturday accused of manslaughter and abandoning the ship before all people were evacuated, and he was due to appear before magistrates for questioning on Tuesday morning. 

Prosecutors say Schettino also refused to go back on board when requested by the coastguard. 

The three explosions were carried out early on Tuesday morning to allow firefighters and scuba divers to enter and leave parts of the ship that they had not yet been able to search. 

"Now we will have better access to the gathering points on the ship, where it seems there might be more chance of finding someone, dead or alive," said firefighters' spokesman Luca Cari.

"They will take micro-cameras in there, and we will be simultaneously looking at the few remaining dry areas and also the wet areas," he said.

Fuel pumping

Pumping the fuel out of the capsized cruise ship will take at least three weeks, the head of the Dutch company in charge of the operation has said.

"That's going to take at least three weeks," Peter Berdowski said in an interview on Dutch television on Monday night when asked how much time his company Royal Boskalis Westminster needed to pump out the fuel on board the stricken Costa Concordia.

When pumping out diesel oil, he added, "every hour counts because if something happens and that spills and there is damage, then you have a very big ecological catastrophe."

Royal Boskalis' subsidiary Smit Salvage will carry out the job of pumping the 2,380 tons of fuel that are in the ship's hold.

The weather improved slightly from Monday but seas were still choppy. 

The giant cruise liner slid a little on Monday, threatening to plunge 2,300 tons of fuel below the Mediterranean waters of the surrounding nature reserve. 

The slippage forced rescuers to suspend efforts to find anyone still alive after three days in the capsized hull, resting on a jagged slope outside the picturesque harbor on the island of Giglio. Six bodies have been found. Most of the 4,200 passengers and crew survived, despite hours of chaos.