Blasts cripple Brazilian oil rig

Petrobras President Henri Reichstul explaining the danger the rig faces

Hopes of finding any of the 10 oil workers missing after two large explosions on a Brazilian oil rig are fading.

Henri Philippe Reichstul, the president of Brazil's oil company, Petrobras, gave the grim assessment, and warned that the rig - the world's largest - could yet sink.

More than 175 people were on board the rig about, about 200km (125 miles) north of Rio de Janeiro, when the blasts occurred early on Thursday.

The rig was extensively damaged and is in danger of sinking

Fire quickly spread, causing extensive damage. Most workers were evacuated, and at least one was seriously injured.

Efforts are now underway to prevent the rig from sinking, but officials say there is little risk of an oil spill.

BBC correspondent Tom Gibb says the national oil company has a very poor record for accidents.

Tilting

The cause of the explosion is still not known. The rig is tilting at an angle of 30 degrees.

Two teams are working around the rig. One is trying to stabilise the rig, using a mini-submarine, and the other is trying to put up barriers as a precaution against oil leaks.

So far, according to Petrobras' president, the accident has not caused serious environmental damage.

Officials say the biggest danger is from the oil and fuel stored on board the rig rather than from the oil well itself, which has been shut off.

Our correspondent says that in other recent oil spills, the quantity of oil which has escaped has turned out to be much larger than first admitted by Petrobras.

Protest called

The oil workers' union says that over the last three years 32 people have died on oil rigs in a total of 99 accidents.

The United Oil Workers Federation (FUP) has criticised Petrobras, accusing the company of putting its workers at risk through cost and personnel cuts.

The FUP urged the country's 34,000 oil workers to join nationwide protests on Friday to demand better working conditions and safety.

Petrobras has also suffered from a series of highly publicised oil spills in the last couple of years, including an environmental disaster in Rio de Janeiro's picturesque bay.

The company has recently announced heavy investments in safety and measures to protect the environment.