CASTRIES, ST. LUCIA -- Residents of the eastern Caribbean island chain of St. Vincent and the Grenadines were advised they could be asked to evacuate their homes on Thursday after a volcano, dormant for decades, came back to life and began spewing ash.

The government raised the alert level to orange for the volcano La Soufriere, indicating that it could erupt within 24 hours.

Steam, gas and a volcanic dome, formed by lava that reaches the Earth's surface, were seen over La Soufriere, located in the northern area of St. Vincent island, the Caribbean Disaster Emergency Management Agency said.

St. Vincent and the Grenadines, which has a population of just over 100,000, has not seen volcanic activity since 1979. An eruption by La Soufriere in 1902 killed more than 1,000 people.

Authorities on the Caribbean island of Martinique, an overseas territory of France, are also closely watching the Mount Pelee volcano there after tremors became more frequent last month, prompting concern among residents.

Mount Pelee has recorded an increase in seismic activity since April 2019, the first activity since the end of an eruption that lasted from 1929 to 1932. Authorities on the island have said a new volcanic eruption could be dangerous.

The simultaneous uptick in activity of La Soufriere and Mount Pelee is not linked, scientists said.

Editing by Cassandra Garrison and Barbara Lewis