Mount Lewotobi Laki-laki, which is in East Nusa Tenggara province, erupted on Tuesday, spewing ash 11 km (6.84 miles) high, forcing the country's volcanology agency to raise the alert level to the highest. 

It erupted again on Wednesday morning, belching a 1 km (0.62 mile) high ash cloud, the agency said in a statement. 

Several international flights from India, Singapore and Australia to Bali were cancelled due to the eruption, the Bali international airport website showed.

Singapore Airlines cancelled four flights between Bali's Denpasar airport and Singapore, and its budget subsidiary Scoot cancelled flights to Bali and the neighbouring island Lombok, the airlines said.

Qantas' low-cost carrier JetStar cancelled several morning flights to Bali from Australia and expects afternoon flights to be delayed. 

"Forecasts show the ash cloud is expected to clear by later tonight," JetStar said in a midday travel bulletin. 

The government closed the Fransiskus Xaverius Seda airport in Maumere from Wednesday until Thursday "to ensure the safety of the passengers," said the airport operator AirNav in its Instagram post. 

The eruption also forced local authorities to evacuate dozens of residents living in two villages near the volcano, Avi Hallan, an official at the local disaster mitigation agency told Reuters.

"Streets in the two villages were filled with thick ash, gravel, and sand," she said, adding no casualties were reported. 

Several domestic AirAsia flights leaving for popular tourist hotspot Labuan Bajo on Flores were also cancelled.

A Bali airport customer service agent told AFP the aviation hub was still operating normally despite the cancelled flights.

"It depends on the route and also the airline," the agent, who declined to give her name, said.

The volcano last erupted in May. 

Volcanic ash rained down on several villages around Lewotobi Laki-Laki and forced the evacuation of at least one village late Tuesday, the National Disaster Mitigation Agency (BNPB) said.

It added tremors were still being detected, which indicated ongoing volcanic activity.

The geology agency said residents and tourists should avoid carrying out any activities within at least seven kilometres of the volcano's crater.

It warned of the possibility of hazardous lahar floods –- a type of mud or debris flow of volcanic materials –- if heavy rain occurs, particularly for communities near rivers. 

There were no immediate reports of damages or casualties.

In November, the volcano erupted multiple times, killing nine people, cancelling scores of international flights to the tourist island of Bali, and forcing thousands to evacuate.