Alaska's Mount Redoubt volcano has sent an ash plume nearly 15 kilometers into the air in its first emissions in nearly 20 years.

This came after geologists recorded six eruptions overnight between Sunday and Monday.

The Alaska Volcano Observatory has said that Mount Redoubt erupted five times shooting plumes of smoke and ash some 15 kilometers (50,000 feet) into the air forcing flight cancellations and putting Alaskan authorities on alert. [Ho/CCTV/AFP/USGS]

A weather radar has confirmed the presence of an ash cloud that climbed to about 18 kilometers above sea level.

Many residents were unprepared because the eruptions took place after the local evening news had aired.

Ash from Alaska's volcanoes is like rock fragments with jagged edges and has been used as an industrial abrasive.

It can injure skin, eyes and breathing passages, as well as damage plane engines, cars and other vehicles. Alaska Airlines has cancelled 19 flights because of the debris in the air.

(CCTV March 25, 2009)