Indonesia's Mount Merapi erupted three times on Tuesday, killing at least 13 people and causing thousands to flee as it emitted searing clouds and volcanic ash.

Twelve bodies were found by rescuers at a house near the volcano and a baby died elsewhere, with predictions that the toll was likely to rise.

Before the latest eruptions people living in the shadow of Indonesia's most active volcano had been warned to evacuate or risk being killed.

"We heard three explosions around 6:00 pm (1100 GMT) spewing volcanic material as high as 1.5 kilometres (one mile) and sending heat clouds down the slopes," government volcanologist Surono told AFP.

Yogyakarta city search and rescue official Taufiq told reporters that 12 people had been killed at one location.

"The bodies were found around the house of Merapi's gatekeeper Mbah (grandfather) Marijan," he said.

"Some were found inside the house, others outside. They were burnt by heat clouds. We've not found Mbah Marijan yet."

The house of Marijan, the traditional spiritual keeper of the mountain, is about four kilometres (2.5 miles) from the peak, in Sleman district.

"There are likely to be more victims as the terrain is difficult, roads are damaged and trees uprooted, it's dark and the condition of the volcano is still unstable," Taufiq added.

Local TV station MetroTV reported that 15 bodies were found in and around the house.

Footage showed Marijan's burnt house and several bodies covered in ash being put in body bags.

Earlier, a doctor at Muntilan hospital, Sasongko, confirmed the death of a baby, telling MetroTV: "The baby had severe breathing difficulties from inhaling volcanic materials and we could not help it."

The baby's death was the first reported fatality from the volcano in central Java, around 25 kilometres (15 miles) north of the cultural capital of Yogyakarta.

At least 24 people were treated at the same hospital for breathing difficulties, while elsewhere five men suffered burns.

Television footage showed thousands of people fleeing in panic, some covered in white ash, as officials with loudhailers tried to help them escape the area.

Authorities had put an area 10 kilometres (six miles) around the crater of Mount Merapi on red alert Monday, ordering 19,000 people to flee.

"This eruption is certainly bigger than the 2006 eruption during which the heat clouds occurred for only seven minutes after the eruption," Surono said.

"Today's eruption released heat clouds of gas and ash down the slopes for about two hours. We cannot tell you how far the searing clouds went down on the slopes because it's dark."

The 2006 blast Surono referred to killed two people.

Officials said nearly 15,000 people had ignored earlier evacuation orders despite several minor blasts that sent lava spewing down Merapi's southern slopes.

Many people sleeping in camps returned to their homes during the day to work and tend to their cattle. Some men refused to leave altogether, confident they would be able to escape.

Field coordinator Widi Sutikno, of the Sleman district on the southern slopes of the mountain, said only about 3,700 people out of 11,400 in his area had sought shelter in makeshift refuges.

Indonesia has more active volcanoes than any other country.

Volcanologists have warned that Merapi, a 2,914-metre (9,616-foot) peak, currently has more energy than before the June 2006 blast, its previous fatal eruption.

Its deadliest eruption occurred in 1930 when more than 1,300 people were killed. Heat clouds from another eruption in 1994 killed more than 60 people.

In August, the 2,460-metre (8,100 foot) Mount Sinabung on the island of Sumatra erupted for the first time in 400 years, sending thousands of people into temporary shelters and disrupting flights.

Mount Sinabung is near Lake Toba, a 100-kilometre long volcanic crater that some archaeologists believe threatened the survival of the human race when it erupted between 69,000 and 77,000 years ago.

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