A St. Vincent volcano has started showing signs of activity after being dormant since its eruption in the 1970s and thousands of residents of the Caribbean island have either fled to neighboring countries or have hunkered down in case of an explosion.

Volcan De la Soufrière was labeled to be in an “explosive state” on Friday after it spewed clouds of ash and started blasting gray smoke into the atmosphere, the New York Times reported.

“The sky, right now it’s very, very dark because of the ash plummeting into the air,” a resident stated.

There have been two explosions in the last 24-hours which sent ash more than 12-miles from the volcano’s location. It's caused for a reason for concern since this could either go on for just a few days or even months, experts have reported.

“Once it has started, it’s possible you could have more explosions,” said Richard Robertson, a professor of geology at the University of the West Indies. “The first bang is not necessarily the biggest bang this volcano will give.”

Pyroclastic flows and surges are also likely to happen and affect the areas that are closest in range to the volcano, so evacuation is crucial, according to CNN.

The eruption in 1979 caused to ash travel 100-miles, all the way to Barbados, but didn’t record any deaths, unlike the 1902 eruption that killed over 1,600 people.

Over 20,000 locals have already been evacuated to various nations that have opened up their borders temporarily including Antigua, St. Lucia, Grenada and Barbados.

Map locating Saint Vincent's La Soufriere volcano, which erupted April 9
Map locating Saint Vincent's La Soufriere volcano, which erupted April 9 AFP / Sofiane OUANES