Students take part in morning exercises at a school at Berastepu village, as Mount Sinabung spews ash in the backgorund, in Karo district, Indonesia's north Sumatra province November 7, 2013. Mount Sinabung continued to spew volcanic ash on Thursday as thousands of residents remained in temporary shelters fearful of more eruptions. Mount Sinabung's last eruption on Tuesday lasted about 20 minutes and sent volcanic ash 3,000 metres into the sky from its crater, authorities said, adding that there were no casualties as everyone in the nearby villages had been moved to shelters. Authorities have put the area surrounding the 2,460-metre high volcano on alert level three, recommending people not to be within a radius of three kilometres from the crater. The students pictured are attending a school outside of the evacuation area. REUTERS/Tarmizy Harva (INDONESIA - Tags: DISASTER ENVIRONMENT EDUCATION SOCIETY)