A helicopter carrying three people went missing near Mount Aso, one of Japan’s most active volcanoes, on Tuesday morning. Local authorities said the aircraft took off from a zoo in Aso city at 10:52 a.m. local time for a 10-minute sightseeing flight but did not return. Later that afternoon, around 4 p.m., a police helicopter spotted an aircraft-like object inside the crater of Mount Aso’s Nakadake volcano, though it has not yet been confirmed as the missing helicopter.

The missing aircraft, a U.S.-made Robinson R44 operated by Takumi Enterprise, was on its third sightseeing trip of the day, with no issues reported on earlier flights. The 64-year-old pilot was described by local media as highly experienced, with about 40 years of flying experience. The passengers were a Taiwanese man and woman.

Cloudy weather was reported in the Nakadake area on Tuesday. Search operations were suspended in the evening due to conditions and resumed Wednesday morning. Following the incident, Takumi Enterprise temporarily grounded all its helicopters, according to Jiji News Agency.