Oil is continuing to leak from the sunken tanker Prestige, say Portuguese officials, as the Spanish clean-up operation accelerates.

An international flotilla of vessels is sailing towards the scene to join the operation, among them a French mini-submarine which should be able to dive to the wreck and assess its condition.

With a disaster of this size, we all have to pitch in

Volunteer

Specialist French and Dutch ships have already started work on tackling oil slicks near the shipwreck site, as up to 600 volunteers scrape up oil that has already been washed ashore.

Up to 60,000 metric tons of fuel oil went down with the ship off the north-western coast, leaving experts to hope that the oil will congeal in the chilly depths.

Many oil workers are students and conservationists

An estimated 1,245 tons of the 11,000 which has escaped has been recovered, the government estimates.

Many seabirds have been killed or coated by the oil, and the area's fishing grounds have been badly affected.

The Spanish authorities on Monday extended a ban on fishing and mussel harvesting to cover around 500 kilometres (315 miles) of affected coastline.

The clean-up volunteers, wearing rubber suits and masks to protect them from the oil's toxic ingredients, have fanned out along 136 beaches hit by the disaster.

"It has to be done," said one volunteer at Seiruga. "With a disaster of this size, we all have to pitch in."

Hundreds of seabirds have been coated in oil

The Greek captain of the Prestige, Apostolus Magouras, has reportedly tod authorities that the crisis began when he ran into a floating container, Spanish papers reported.

He described "a very loud sound" at the moment of impact, before the tanker began to list and take on water.

He remains under Spanish detention until the cause of the problem is verified.

The initial cost of the disaster to the local economy has been estimated at 42 million euros, but there are fears that figure could rise dramatically.

Fishermen hit by the disaster are being paid compensation of 40 euros a day.

They are facing the loss of trading over the lucrative Christmas period.

Hotels and other tourist facilities, such as car hire, have enjoyed a temporary unseasonal boom as journalists and clean-up workers flock to the coastline.

Government challenged

Deputy Prime Minister Mariano Rajoy has given optimistic assessments about the scale of the disaster, insisting that the situation is under control and that the leaks have stopped.

But some Spanish newspapers and environmental groups have contested the government's reassuring attitude.

Greenpeace says the amount of escaped oil is twice as big as the government has acknowledged, and that it is still emerging.

The Portuguese navy, whose planes have been flying over the shipwreck site, also says that some oil has continued leaking, although in smaller quantities.

Fresh oil

Only slight traces of fuel oil were spotted on Sunday, said Captain Augusto Ezequiel of the navy's Hydrographic Institute.

"That would indicate that the upwellings are tending to lessen, that the quantity of fuel oil that is coming to the surface is less," he said.

Fears of a new slick coming ashore in Spain or Portugal have receded slightly, as southwesterly winds drove the slick away from land.

Public anger in Spain has continued to grow.

Galicia's La Opinion newspaper said the authorities' handling of the emergency had caused a "shipwreck of confidence", while Vanguardia newspaper described a "A Tide of Discontent".