Thursday Montserrat Volcano Observatory director, Dr. Sue Loughlin reported that the alert level for the Soufriere Hills volcano was raised to four on a scale of 0-5.
She reported that lava had been coming up to the surface at fast rate, following increased earth tremors and gas venting.
Residents in the southern inhabited areas Salem, Old Towne, Olveston could hear familar jet-plane like sounds since last night.
The MVO director said "There are tremors ongoing which have picked up since about 8.30 a.m. still on going at noon, we decided to put the alert level up to four.
"There has been a lot of ash venting and an increase in the number of earthquakes.
"We can expect to see perhaps pyroclastic flows and more ash and something possibly a dome collapse within a day or two," she said.
Yesterday there were visible pyroclastic flows down the northeastern side of the dome.
"The Gages wall area on the south side (which overlooks Plymouth the old abandoned capiral) in the exclusion one of the new vents opened this morning just inside the Gages wall."
She reported that the size of the dome is of the order of 55 milion cubic metres - relatively unstable with a high summit - quite tall - it can grow for months without anything happening, but any activity like we are experiencing, we can expect some changes."
Meanwhile this preliminary assessment was issued only moments after the announcement came, preceded by wailing sounds from the siren.
These photos posted courtesy Montserrat Volcano Observatory - dated Aug. 31, 2006