Mount Lewotobi Laki-Laki, a 1,584-metre-high twin-peaked volcano on Flores island, launched into a series of eruptions Friday evening, with the largest at 10:46 pm local time sending volcanic material six kilometres (nealy four miles) above its peak, the volcanology agency said in a statement.

Volcanic activities resumed on Saturday morning, with the agency recording several eruptions including one that sent an ash tower 2.5 kilometres into the sky.

The eruptions came after the geology agency raised the volcano's alert level to the highest of Indonesia's four-tiered system on Friday night.

Geology agency head Muhammad Wafid warned residents and tourists to stay at least six kilometres from the volcano's crater and said volcanic ash could disrupt airport operations.

"Volcanic ash from Mount Lewotobi Laki-Laki's eruption could also disrupt airport operations and flight paths if it spreads towards the airport area and aircraft routes," he said in a statement.

Residents, particularly for communities near rivers, should also be on alert for the possibility of hazardous lahar floods -- a type of mud or debris flow of volcanic materials -- if heavy rain occurs, Wafid added.

An airport that serves domestic flights in the town of Maumere, also on Flores, suspended its operations following the eruptions.

Frans Seda airport head Partahian Panjaitan told AFP authorities would monitor developments on Sunday before deciding whether to reopen.

In July, the volcano spewed a colossal 18-kilometre tower of ash, forcing the cancellation of 24 flights at the international airport on the resort island of Bali.

Bali's airport was operating normally without disruption Saturday, spokesperson Gede Eka Sandi Asmadi told AFP.

Laki-Laki, which means man in Indonesian, is twinned with the calmer but taller 1,703-metre (5,587-foot) volcano named Perempuan, after the Indonesian word for woman.

Indonesia, a vast archipelago nation, experiences frequent seismic and volcanic activity due to its position on the Pacific "Ring of Fire".