Oil leaking from a ruptured well pipe in the Gulf of Mexico washed ashore in two new locations yesterday, the Coast Guard said, as the latest attempt to contain the spill faltered.

Efforts to siphon leaking oil via an 'insertion tube' up to a container vessel continued a day after US President Barack Obama blasted oil companies for seeking to shift blame for a growing oil slick threatening environmental disaster.

Petty Officer Erik Swanson told AFP yesterday that oil from a riser pipe that ruptured after the collapse of the Deepwater Horizon rig had been discovered in two new locations - Whiskey Island, Louisiana and Long Beach, Mississippi.

"We sent crews to assess what type of oil, and we determined it's 'soft patties' on Whiskey Island and 'tarballs' on Long Beach," he said.

Tarballs are small globs of oil, while soft patties are roughly six inches in diameter and more than a centimetre thick, he said.

The appearance of oil in new locations is a sign of the urgency of efforts to contain the spill, which experts warn may be growing more than 10 times faster than previous Coast Guard estimates of 5,000 barrels (210,000 gallons) a day.

Scientists who analysed the flow of oil in a video of the underwater leak fear the rate may be closer to 70,000 barrels (2.9 million gallons) a day. The findings suggest the spill has already eclipsed the 1989 Exxon Valdez spill, which was the worst environmental disaster in US history.

BP disputes the figures, with Robert Dudley, BP's executive vice- president for the Americas, telling CNN that "70,000 barrels a day isn't anywhere I think within the realm of possibility".

Last Friday, a visibly angry Obama chastised British Petroleum, Transocean and Halliburton - the firms that leased, owned and worked on the rig - for seeking to shirk responsibility for the disaster.

He said top company officials had created a "ridiculous spectacle" in testimony before Congress and warned he would "not tolerate more finger pointing or irresponsibility".

BP, which leased the ill-fated Deepwater rig from Transocean, has pledged to pay for the costs of containing, capping and cleaning up the oil spill, and to compensate any "legitimate" claims stemming from the leak.

But multiple efforts over the past three weeks to stop the leak, or even to slow the flow of oil, have failed, and the latest attempt on Saturday was proving more difficult than expected.

BP crews, using remote-controlled submarines, struggled to place an 'insertion tube' into the leaking riser 1.6 kilometres down on the seabed.

Once inserted, the tube should be able to funnel the leaking oil up to a container vessel on the ocean surface, though the method is untested.

"We were hoping it was going to be operational last night," BP spokesman John Crabtree said, acknowledging that the process was proving more complicated than expected.

It was unclear why engineers had failed to connect the tube, and how long they would keep trying before turning to alternative methods.

BP has already deployed to the seabed a so-called 'top hat' container, which is attached to a siphon tube and could be lowered over the leak to collect and then funnel away the oil.

The method has been tried once before, but low temperatures and high pressure caused the oil to form sludge that could not be funnelled away, so the container has been redesigned with a heating system.

Another option is the 'junk shot', which would involve trying to plug the leak with assorted junk, including knotted rope, plastic cubes and even golf balls. The process could halt the flow altogether or at least slow the spill.

The slick has the potential to devastate fragile and environmentally important coastline across a region where many are still recovering from the effects of Hurricane Katrina in 2005.

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.