Iceland closed its main international airport and canceled domestic flights on Sunday as the country's most active Grimsvotn volcano's eruption sent a plume of ash, smoke and steam high into the sky.

The eruption began at 5:30 p.m. on Saturday, according to the Icelandic Met(eorological) Office. The plume initially reached approximately 20 kilometers in altitude. Early Sunday, the height varied from between 10 kilometers and 15 kilometers.

Lightning activity in the area around the volcano was much more intense - about 1000 times more - than during the Eyjafjallajokull Eruption.

“The ash from a new volcanic eruption could reach U.K domestic airspace by Tuesday.” U.K. Civil Aviation Authority said in a statement.