Jakarta. Mount Merapi in Yogyakarta erupted twice overnight on Friday (01/06), prompting dozens of residents still living inside the 3-kilometer danger zone around the volcano to flee their homes.

The Center for Research and Development of Geological Disaster Technology (BPPTKG) said the first eruption occurred at 20.24 p.m. and another 36 minutes later.

Friday's night eruption prompted 98 people to flee their homes in three hamlets on the slope of Mount Merapi and take refuge in nearby Glagaharjo village, Makwan, head of emergency and logistics at the Sleman District Disaster Management Agency, said on Saturday, as quoted by Antara.

They were among the last people still remaining in the danger zone despite warnings from the authorities to leave the area.

The volcano has become increasingly more active since May 11, spewing columns of ash hundreds of kilometers into the sky and disrupting fights to and from nearby Adisoetjipto International Airport.

The National Disaster Management Agency (BNPB) said all the eruptions so far had been phreatic, which means that they were caused by heated steam inside the cauldron, as opposed to magmatic eruptions, which include lava ejection.

The agency has raised the danger level to the second highest level since May 22, warning residents against staying in the danger zone.

Following the deadly 2010 Merapi eruption, the government has been working to move 3,413 of the 4,000 households living inside the danger zone to safer areas.

The 2010 eruption displaced 350,000 people and killed 353, most of them in pyroclastic flows, after they ignored government warnings to vacate the area.