Authorities closed Sicily's Catania airport on Thursday after streams of red hot lava spewed from Mount Etna covering the skies in black smoke and ash.

Volcanic activity from Etna's 'Voragine' crater has intensified this week with vigorous explosions and incandescent shreds following a four-year silence.

Etna and Stromboli are the most explosive volcanoes due to the composition of the magma, and they can erupt more explosively due to minute variations in the chemical composition of their magma.

The 3,330-meter-high volcano Mount Etna, Europe's tallest active volcano, is believed to have the longest documented history of eruptions among all volcanoes, with records dating back to as early as 425 B.C.