Indonesia's volcano in dessely populated Central Java erupted on Tuesday afternoon, spewing hot ashes, pushing thousands of people to evacuate, head of volcanology monitoring unit at Volcanology Afgency Muhammad Hendratno said.

Mount Merapi of 2,968 meters high erupted three times, with the first eruption at 17:02 p.m. Jakarta time (1002 GMT), Hendratmo told Xinhua.

He said that the eruption was the beginning of eruption phase.

Obsever at monitoring post for Mount Merapi in Sleman district of Yoyakarta Heru Saparwoko told Xinhua by phone from the district that cloud had hampered them to monitor how far the hot ash spread. "We will keep monitoring the peak of eruption," he said.

Metro television footage show a massive evacuation of thosse from the slope of the mount. Some people sustained injury caused by hot ash.