The Associated Press reports, "Coast Guard Adm. Thad Allen is saying that a saw has become stuck as it was cutting through a pipe on a busted well, stalling the latest attempt to contain the Gulf oil gusher."

The AP adds, "Allen said Wednesday the goal is to free the saw and finish the cut later in the day. This is the second major cut in the effort to contain — not plug — the nation's worst spill."

Oil closes in on Florida coast

The giant Gulf of Mexico oil slick was Wednesday closing in on the pristine Florida coast, as deep sea robotic submarines worked on BP's latest bid to contain the spill.

Forecasters said it was virtually certain Florida's panhandle, a major draw for tourists from around the world, would be hit by the spill this week.

A Florida official told AFP the latest official projections from the National Oceanic and Atmospheric Administration (NOAA) show the slick to be about seven miles (11 kilometers) off the state's shores.

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"Within the next 72 hours it should affect our coast," the official with Florida's Environmental Protection Agency said Wednesday.

Florida would be the fourth state hit by the oil since an April 20 explosion ripped through the Deepwater Horizon rig, 50 miles (80 kilometers) off the Louisiana coast, killing 11 workers. The BP-operated rig sank two days later.

More than 125 miles (200 kilometers) of Louisiana coast has since been contaminated by the oil, which has also been spotted on Alabama and Mississippi shores, amid fears for the region's already endangered wildlife.

With the ribbons of oil spreading, US officials extended new fishing restrictions, with about one-third of the Gulf of Mexico off limits.

NOAA said the ban was expanded "to capture portions of the slick moving into waters off eastern Alabama and the western tip of the Florida panhandle, as well as some large patches of sheen moving onto the west Florida shelf and southward to Cuban waters."

As the British energy giant battles to contain the six-week spill now the worst in US history, robotic submarines succeeded late Tuesday in making the first clean cut to the end of the fractured pipe.

The next step will be to try to cap the end of the pipeline and then siphon the oil to a containment ship on surface.

Underwater robots cut away pipes around the main riser pipe, and then moved in with a diamond wire cutter to cleanly sever the main riser pipe, officials said.

BP's chief operating officer Doug Suttles said the cap should be installed on the pipe later Wednesday, but acknowledged that until it is in place the flow of oil into the Gulf would likely increase by as much as 20 percent.

The US government has estimated the flow of oil before the riser was cut away at 12,000 to 19,000 barrels a day -- meaning at least 20 million gallons have poured into the Gulf since April.

"I think if this works, we should capture the vast majority of the flow," Suttles said on CNN Tuesday.

"We can't say it'll capture all of it, because it's not a tight mechanical seal, but if it functions well it should capture the vast majority of the flow."

As BP works to drill two relief wells to permanently stop the leak which will not be in place until August, US officials on Tuesday said the environmental disaster now was the subject of a criminal probe.

In New Orleans, Attorney General Eric Holder told reporters his office "will prosecute to the fullest extent of the law anyone who has violated the law."

Holder said the criminal probe began "some weeks ago" but declined to elaborate on what kind of charges could be brought and against whom.

US President Barack Obama has also threatened to take legal action against those to blame, saying the government had an "obligation" to determine the cause of the "greatest environmental disaster of its kind in our history."

"If our laws were broken leading to this death and destruction, my solemn pledge is that we will bring those responsible to justice on behalf of the victims of this catastrophe and the people of the Gulf region," Obama vowed.

BP shares plunged 13 percent on Tuesday, wiping off 12 billion pounds (17.6 billion US dollars) off its market value after a string of failures to plug the leak. The company also acknowledged that it spent a billion pounds on dealing with the disaster.

Tuesday's official start of the hurricane season has worsened the outlook for Gulf residents, amid warnings the 2010 storm season will be more than active than usual, with up to 14 hurricanes.

(with additional reporting by Raw Story)