The 2,963 meter high Merapi is one of the most active volcanoes in Indonesia and is already at the second highest alarm level in the country.
Kasbani, the head of the Indonesian Volcanological and Geological Center for Risk Mitigation, said that Merapi had been discharging “pretty intense” hot clouds at least 30 times since Wednesday morning and warned of the danger of lava excisions near the volcano.
Photos shared on social media showed ash covering the homes of some nearby residents.
There were no immediate reports of damage, but some residents had chosen to leave their homes, the local disaster relief agency said.
Indonesia, located on the so-called “Ring of Fire”, has more volcanoes than any other country and Merapi erupted violently in 2010, killing more than 350 people.
The eruption comes just weeks after a magnitude 6.2 earthquake on the Indonesian island of Sulawesi, which razed buildings and killed dozens.