REYKAJVIK, Iceland - A volcano erupted in a remote area of Iceland on Monday, setting off tremors across the area and prompting officials to warn pilots to avoid flying through gasses being emitted by the blast.

No evacuations were needed in the unpopulated area around Grimsvotn mountain in eastern Iceland, the Meteorological Office said, but visual confirmation of the damage being done was impossible because heavy winds and rains reduced visibility in the area.

The eruption was believed to have been caused by expansion of a lake underneath the Vatnajokull glacier.

"The water is under extreme pressure from the glacier. We believe it could open a part of the Grimsvotn mountain, causing the release of some magma, though this cannot be confirmed without visual identification," said Oli Thor Arnarsson at the Meteorological Office.

His office issued the warning to pilots on Monday evening.

Grimsvotn last erupted six years ago. It also erupted in 1995 and 1993, causing flooding.

The mountain lies on the Atlantic Rift, the meeting of the Euro and American continental plates. The three major volcanoes of Iceland - Hekla, Katla and Grimsvotn - lie on the same fault line. Hekla last erupted in 2000.