Iceland's New Volcano Erupts, Lights Up Sky with Molten Rock, Lava Flows

Iceland is putting on a spectacular, and dangerous, display of volcanic power ... as the eruption of a new volcano throws plumes of lava in the sky, following weeks of increased seismic activity.

A public state of emergency was declared as the Grindavík volcano exploded Monday ... just south of the Keflavik International Airport and the capital city of Reykjavík, and video footage shows molten rock exploding up to 300 feet into the air.

The eruption created a 2.5-mile fissure, which sent a stream of lava flowing through the surrounding towns ... while hundreds of cubic meters spewed across the Reykjanes peninsula.

The Icelandic Meteorological Office listed the time of eruption at 10:17 PM ... after closely monitoring seismic activity in the area for a while.

The flow has slowed since its peak on Monday evening ... and lava fountains have fallen from 300 to 100 ft.

However, evacuated areas are still off-limits, and authorities remain on high alert ... with local experts warning it's possible several more cracks could open in the ground.