Oil giant BP has succeeded in placing a containment cap over the ruptured well head that is gushing oil into the Gulf of Mexico, but was to spend Friday sealing the cap and closing valves before it could capture much of the oil.

'Progress is being made,' said Coast Guard Admiral Thad Allen, who is leading the government?s response to the oil spill.

The small containment dome is designed to capture most of the oil and siphon it up to the surface, but Allen said it would not be clear until later Friday just how successful the operation has been.

The progress comes as winds continued to drive the worst oil spill in US history further eastward towards Florida's popular panhandle beaches.

'Extraordinarily wide' area

Clean-up crews were now battling the oil over an 'extraordinarily wide' area that stretched from Louisiana to Pensacola, Florida, according to Admiral Allen. The Coast Guard was also looking into reports of an 'oily substance' and tar balls near three islands in the Florida Keys.

'The scope of this thing is starting to extend to the point where it's rather unprecedented,' he said.

Whether or not the containment cap succeeds in siphoning most of the oil, officials stressed it was a temporary solution. Two relief wells are being drilled that could permanently seal off the underwater leak, but these will not be finished until August.

'Even if successful, this is only a temporary and partial fix and we must continue our aggressive response operations at the source, on the surface and along the Gulf's precious coastline,' Admiral Allen said.

Portion of pipe cut

BP on Thursday managed to cut a portion of pipe that was leaking oil, but the cut was not as fine as hopes, forcing the use of a slightly wider containment cap. Engineers, using robotic submarines operating at the ocean floor, then slowly placed the 'top cap' over the marine riser pipe.