JAKARTA, Indonesia -- Indonesian authorities raised the alert for the country's most volatile volcano, located on the densely populated island of Java, and ordered people within three kilometers (two miles) to evacuate.
Mount Merapi has erupted four times since Monday, sending out a 3,500-meter (11,483 feet) column of volcanic material and dusting the surrounding region in ash.
Sutopo Purwo Nugroho, the national disaster mitigation agency's spokesman, said some 660 people living within the exclusion zone have evacuated since early Tuesday, May 22.
Indonesia's geological agency raised Merapi's alert from normal to "beware," because of its increased activity.
There have been no reports of casualties and operations at Adi Sucipto airport in Yogyakarta have not been affected.
The 2,968-meter (9,737-foot) mountain is about 30 kilometers (18 miles) from the Yogyakarta city center is the most active of more than 120 active Indonesian volcanoes.
Its last major eruption in 2010 killed 347 people and caused the evacuation of 20,000 villagers.
Nugroho said climbing on Merapi is prohibited and only disaster agency personnel or related researchers should enter the restricted area.
Indonesia, an archipelago of more than 250 million people, sits on the Pacific "Ring of Fire" and is prone to earthquakes and volcanic eruptions. (AP)