JAKARTA, May 24 (Xinhua) -- Mount Merapi, the most active volcano situated in Java Island of Indonesia, erupted earlier Thursday sending an ash column as high as 6,000 meters into the sky, Head of National Volcanology Agency Kasbani said.

The eruption, which occurred at 2:55 a.m. Jakarta time (1955 GMT Wednesday), was followed by the issuance of poisonous gases, such as H2S and CO2, from the crater, Kasbani said.

"The volcanic gases are dangerous in the areas around the crater, Therefor we restrict activities in the radius of 3 km. These gases were on hot condition and created pressure that led them to exit," he told Xinhua by phone.

The official suggested residents in nearby regions set up preparation measures, including using mask.

"Volcanic ashes can be spread far away from the crater by wind blows," Kasbani said.

During Tuesday's eruption the volcano forced about 660 people to flee homes, according to the national disaster management agency.

Mount Merapi, situated on the borders of Central Java and Yogyakarta province, is about 28 km north of Yogyakarta city, which has a population of 2.4 million. Thousands of people live on the flanks of the volcano.

Mount Merapi volcano, one of Indonesia's 129 active volcanoes, has been regularly erupting since 1948. In November 1994, pyroclastic flow from a large explosion killed 27 people. Another large eruption occurred in 2006.