Indonesian rescuers Thursday were struggling to evacuate two people trapped inside an underground bunker which was buried by volcanic debris on the slope of Merapi mountain in Yogyakarta province.

The two were believed to seek shelter in the bunker shortly after the volcano belched hot clouds over a distance of 7 kilometers from the crater, reported the national Antara news agency.

However, volcanic materials blocked entrance, making it difficult for the evacuation effort, a rescue worker was quoted as saying.

Evacuation was also hampered by hot ash and sand.

"Actually, drinking water and oxygen are available in the bunker. But I am afraid they cannot use it," said Susilo, member of natural disaster mitigation task force.

Volcanic activities of the 3,000-meter volcano have calmed down but on Wednesday officials again announced the highest alert status after it spewed hot clouds to nearby villages.

Source: Xinhua