Hurricane Rita, weakened and downgraded to a category three storm, continued to move ahead at 125 mph on Friday, ripping through the Gulf of Mexico and gearing to slam into the American coast's oil refining facilities on Saturday.

"A further slow weakening is possible before landfall... but Rita is still expected to come ashore as a dangerous hurricane," the National Hurricane Center said in a bulletin at 1800 GMT (2330 IST), after downgrading it to level three in the five point Saffir-Simpson scale.

The Rita effect: Highways turn near death traps

Earlier, the killer storm took a turn towards the east, and may spare Houston and Galveston a direct hit. The storm will still deliver intense and heavy rain.

Galveston has already started flooding not because of rains but due to tides.

Meanwhile, authorities on Friday advised Houston residents who were still at home at this point to stay there.

President George W Bush, ahead of a visit to Colorado, said people were working very hard to help prepare for the storm.

"We are now facing yet another big storm... and the folks here... are working so hard to help the folks on the ground prepare for the storm," he said at a Federal Emergency Management facility in Washington.

Texas: 20 dead in fire aboard evacuees' bus

He will visit San Antonio in Texas for inspections and then go to the Northern Command headquarters.

"Our job is to assist, prepare for and assist the state and local people to save lives and to help these people get back on their feet," he said.

His entourage will see to it that it "does not get in the way of people doing their job, which will be search and rescue immediately," he added.

Meanwhile in rainy New Orleans, water poured over a patched levee, gushing into the city's hard-hit but largely empty Ninth Ward and heightening fears that Rita would flood the devastated city all over again.

"Our worst fears came true," said Maj Barry Guidry of the Georgia National Guard.

"We have three significant breaches in the levee and the water is rising rapidly."

At 10 am local time, Rita was centered about 220 miles southeast of Galveston and was moving to the northwest at 10 mph. Its winds were near 135 mph, down from 175 mph on Thursday.