Mount Bromo erupted at around 3:20 pm (0820 GMT), said a policeman on duty in the town of Probolinggo, adding that the two who died were Indonesians from Bali island.

But a search and rescue chief on the mountain, Ahmadi Utomo, said one of the two men killed by falling rocks was a Singaporean.

"I saw his passport and other identification cards which showed that he is Singaporean," Utomo told AFP by phone. The other man who died was Indonesian, he said.

It was the second eruption Tuesday in the Indonesian archipelago, which sits on the so-called "Pacific Rim of Fire" noted for its volcanic and seismic activity.

In the northern island of Sangihe hundreds of miles northeast of Java, local officials said about 20,000 people had been evacuated from the slopes of 1,320-meter (4,356-foot) Mount Awu, which has begun showering hot ash on villages.

"There are already small eruptions and the emission of smoke and volcanic ash," said Samuel Dolompaha, from the monitoring station on the island north of Sulawesi.

He said the wind-blown ash from Mount Awu has fallen on villages but the evacuation from danger zones was believed almost completed.

Local welfare official Makasenda said villagers have been moved to the island's main town of Tahuna and were sheltering in government buildings, schools and places of worship. She said the evacuation was continuing.

The vulcanology office on Sunday raised the status on Mount Awu to "beware", the highest alert level.

Mount Awu last erupted in 1992 but caused no casualties. A major eruption in August 1966 killed 39 people and caused thousands to flee.

Smoke and ash rose some three kilometers above the crater of 2,392-meter (7,894-foot) Mount Bromo.

"The sky is dark and the ash is painful to the eyes," said a policeman in the city of Malang, some 40 kilometers (25 miles) to the west.

A worker at Ngadisari health clinic near the volcano said two men and three women were hurt, mostly by falling rocks. One of the women broke her leg.

Geologists said the eruption was mostly steam from water that seeped into the volcano and came into contact with the magma.

"Now the eruption has calmed and it is only steam," vulcanologist Mas Ace Purbawinata told local radio, saying he expects the volcanic activity will soon dissipate further.

TERRA.WIRE