The Mount St. Helens volcano, which roared suddenly to life with a giant plume of steam and ash, remains dangerous and could erupt again at any time, scientists have warned.
Tom Pierson, geologist with the US Geological Survey, said an eruption was imminent.
He said the threat level for St Helens was raised to a level-three "&to=http:// english.pravda.ru/society/2003/01/29/42716.html ' target=_blank>volcano alert", the highest eruption risk level.
Mr Pierson said authorities were evacuating everyone from a 8 km radius of the mountain.
He said a string of small earthquakes recorded in and under the mountain early Saturday had subsided to a low, constant rumble.
"They've moved into just pure tremor," he said, reports Melbourne Herald Sun.
According to the Reuters, Willie Scott, a U.S. Geological Survey geologist, said that tremors were detected in the crater of Mount St. Helens at 3 a.m. (1000 GMT) that indicated that a second eruption could be in store after Friday's minor explosion that sent up a plume of steam and ash.
The U.S. Geological Survey kept its warning level at a Level 3-Volcano Alert and kept off-limits a visitor center at the Johnston Ridge Observatory about five miles from the &to=http:// english.pravda.ru/main/2003/07/28/48844.html ' target=_blank>volcano's crater as a safety precaution.
Gases were also detected for the second day, Scott said, suggesting that magma may be building up underneath the crater's lava dome created after a 1980 eruption which killed 57 people, destroyed more than 200 homes, devastated hundreds of square miles, and sent ash drifting across &to=http:// english.pravda.ru/comp/2002/04/18/27761.html ' target=_blank>North America as far east as Oklahoma.