Experts are concerned that the lava from the volcano could create clouds of toxic hydrochloric acid vapor if it reaches the sea. While one of the two lava rivers has slowed, the other has picked up pace. Reports on Tuesday suggested one is just 800 meters from the sea.

Authorities have been expecting the lava to reach the sea for days, but volcanic activity has been erratic, somewhat slowing the progress of the red-hot rivers. However, activity picked up again overnight, heightening concerns.

While thousands have been relocated, many remain hunkered down in coastal villages in anticipation of the molten flow reaching the Atlantic Ocean. Three villages were locked down on Monday in expectation, with residents told to keep windows closed and stay indoors.

To date, no fatalities or serious injuries have been reported since the eruptions began.