Indonesian authorities urged more than 100 domestic and foreign tourists to leave Mount Rinjani on the resort island of Lombok on Wednesday after a volcano erupted there.
Mount Barujari, a sub-volcano of Mount Rinjani, erupted Tuesday sending ash 2,000 metres into the sky.
No one was known to have been harmed, said Heronimus Guru, an official at the National Search and Rescue Agency.
"There were 112 tourists and they have been accounted for," Heronimus said. "They wanted to capture the moment and take photographs."
He said that authorities had sent a team to tell them to come down.
Earlier Sutopo Nugroho, spokesman for the National Disaster Management Agency, said 389 tourists, including 333 foreigners, were registered to be climbing the volcano on Tuesday.
Authorities have advised people to stay outside a three-kilometre exclusion zone.
Mount Barujari has been particularly active since last year, spewing ash that has disrupted flights serving Lombok and the nearby resort island of Bali.