ST. JOHN'S, Montserrat (AP) _ The government began urging residents to evacuate this island today as violent tropical storms approached from the east, knocking down tents of those who had already fled an unstable volcano.

``We're encouraging people who have families on neighboring islands to leave the island,'' said National Disaster Coordinator Juliette Brade, speaking to reporters at a school that had been turned into a hospital.

Parts of this British colony, located in the Caribbean some 1,200 miles southeast of Miami, had been evacuated this week after the long-dormant Soufrierre Hills volcano blew a plume of ash, steam and noxious gases 7,000 feet into the air Monday.

The ashes engulfed Plymouth, plunging the capital into darkness for half an hour, and forced 6,000 of the tiny island's 12,000 residents to evacuate.

More than 1,500 people flew out Wednesday and Thursday on special shuttle flights to neighboring island nations. Those who stayed are now anxiously following reports on the progress of Hurricane Humberto and Tropical Storm Iris in the Atlantic Ocean.

A separate tropical squall hit the island late Thursday. At a tent city where 700 evacuees were staying, gusty winds wrenched corrugated iron sheeting from shower stalls and the kitchen and sent them crashing into the U.S. military-issued tents.

Other tents were blown down and several children were separated from their parents in the chaos that followed.

On the volcano front, three new vents erupted this week, government information officer Claude Hogan announced today on state-run Radio Montserrat. Scientists say there is a strong chance the volcano, which has been smoldering since July 18, could explode.

The radio also broadcasted reports today on the progress of Hurricane Humberto, with 105 mph winds, and Iris, downgraded from hurricane to tropical storm with 65 mph winds, as they pushed toward the Caribbean.

They are expected to bring much stronger winds than the gusts that created the havoc Thursday night.

The U.S. National Hurricane Center posted a tropical storm watch today for the northeastern Lesser Antilles, including Dominica, Antigua, Barbuda and St. Kitts. Antigua is only a 12-minute flight from Montserrat.