Officials in Indonesia have raised the alert level for a volcano on the resort island of Bali to the highest threshold over fears an eruption could be imminent.

Thousands of residents and tourists were evacuated from villages near the Mount Agung volcano, which last erupted more than 50 years ago.

Authorities have warned people to avoid hiking within a 9-kilometer radius from the crater, which has been blowing smoke over the popular tourist site.

Hundreds of small tremors this week also have rattled the mountain, which is about 70 kilometers northeast of the tourist hot spot of Kuta. Officials say nearly 10,000 people have been evacuated from the area and more evacuations are expected.

"Volcanic activity remains high and there are indications of magma rising to the surface," said Sutopo Purwo Nugroho of the National Disaster Management Agency. "There should be zero public activity within the specified radius in case there is an eruption."

