An active volcano near Alaska's most populated city could be on the brink of eruption, according to scientists who are constantly monitoring a potential threat.

Mount Etna, standing around 3,300 meters (10,800 feet) high, erupts with smoke streaming from its summit and lava spilling from the new “Bocca Nuova” crater, according to Reuters.

Scientists are keeping a close eye on three US volcanoes after their threat levels rose Thursday, suggesting eruptions may be imminent. One already blew this week, spewing lava, ash and gas ...

Watch: These Indonesian tourists perfectly capture on camera an erupting volcano from a shockingly close-up view.