A volcano that has been rumbling for months unleased a major eruption in Indonesia on Saturday, killing 14 people, officials said, a day after authorities allowed thousands of villagers who had been evacuated to return to the volcano’s slopes.

Among the dead on Mount Sinabung were a local television journalist and four high-school students and their teacher who were visiting the mountain to see the eruptions up close, according to Sutopo Purwo Nugroho, a National Disaster Mitigation Agency spokesman. At least three other people were injured, and authorities said they feared the death toll would rise.

Sinabung, in western Sumatra, has been erupting for four months, sending lava and searing gas and rocks rolling down its southern slopes. Authorities had evacuated more than 30,000 people, housing them in tents, schools and public buildings. Many have been desperate to return to check on homes and farms, presenting a quandary for the government.

On Friday, authorities allowed nearly 14,000 people living outside a three-mile danger zone to return home after volcanic activity eased. Others living close to the peak have been returning to their homes over the past four months despite the dangers.

On Saturday, a series of huge blasts and eruptions thundered from the 8,530-foot-high volcano, sending lava and pyroclastic flows up to nearly three miles away, Nugroho said. Television footage showed villages, farms and trees around the volcano covered in thick gray ash.

After the eruption, all those who had been allowed to return home Friday were ordered back into evacuation centers.

“The death toll is likely to rise, as many people are reported still missing and the darkness hampered our rescue efforts,” said Lt. Col. Asep Sukarna, who led the operation to retrieve charred corpses some two miles from the volcano’s peak.

Indonesia is prone to seismic upheaval because of its location on the Pacific “Ring of Fire,” an arc of volcanoes and fault lines encircling the Pacific Basin. Mount Sinabung is one of about 130 active volcanoes in Indonesia and has erupted sporadically since September.

In 2010, Indonesia’s most volatile volcano, Mount Merapi, roared to life, killing 324 people over two months. As now in Sinabung, authorities struggled to keep people away from the mountain. Scientists monitor Merapi, Sinabung and other Indonesian volcanoes nonstop, but predicting their activity with any accuracy is all but impossible.

The latest eruptions came a week after President Susilo Bambang Yudhoyono visited displaced villagers in Sinabung and pledged to relocate them away from the mountain. Villagers are attracted to the slopes of volcanoes because the eruptions make for fertile soil.

Sinabung’s last major eruption was in August 2010, when it killed two people. Before that, it had been quiet for four centuries.

— Associated Press