Volcano in Central Java of Indonesia re-erupted on Wednesday afternoon, the strongest since last week, unleashing hot ash continuously for more than one hour by up to 10 kilometers and forcing authorities to extend dangerous zone which lead to the evacuation of over thousands of people, officials said.

Mount Merapi volcano spews smoke as it erupted again on Wednesday as seen from Sidorejo village in Klaten, near the ancient city of Yogyakarta, November 3, 2010. [Xinhua/Reuters]

Mount Merapi of 2,968 meters high exploded from 14:00 p.m. Jakarta time (0700 GMT) to 16:20 p.m. Jakarta time (0920 GMT), volcanology agency extended dangerous zone from 10 kilometers to 15 kilometers, official at the Volcanology Agency in Yogyakarta named only Ismail told Xinhua.

Head of the agency who goes with single name Surono told a local television that the spewing of hot ash for more than one hour had been rare, indicating the worst situation so far. "Mount Merapi has entered crisis period," he said. Ismail said that the hot ash spread to southern but its height could be confirm due to heavy clouds.

National Disaster Management Agency spokesperson Nelis Zuliasri said that there were 733,335 people in the radius of 15 kilometers from the volcano.

The figure included those have already taken shelters from the area of 10 kilometers from the mount, he said. "The area in the radius of 15 kilometers must be sterilized, all the people must leave," she told Xinhua by phone from Jakarta. "All our strength, including soldiers, police, volunteers and authorities must be deployed to displace all the persons," said Zuliastri.

In Pakem sub-district of Sleman district, residents were panic, many of them left the area under the rains, and some others searched those still stay at the radius of 10 kilometers or near the area for evacuation.

"We will ask those still stay in the radius of 10 to 15 kilometers to leave the area," coordinator at cording post for Sleman district Taupik Wahyudi told Xinhua.

Previously, the residents have left the area at the radius of 10 kilometers and taken shelters near the area, and they regularly return to their homes at the dangerous zones to take care their cattle.

The Merapi volcano first erupted on Oct. 26.

Mount Merapi is one of Indonesia's most active volcanoes. The Southeast Asian country lies in a quake-prone zone called the Pacific Ring of Fire, and now has 129 active volcanoes.

The previous eruption of Mount Merapi in 2006 killed two people. A 1994 eruption claimed 60 people's lives. A major eruption in 1930 killed more than 1,000 people.