Farmers tended sugar cane and children rode bicycles in the shadow of a killer Indonesian volcano on Sunday, defying warnings by scientists that the smoking mountain was poised for a powerful eruption.

The top scientist monitoring Mount Kelud said the temperature of its crater lake had reached 76 degrees Celsius (168 Fahrenheit) — a rise of more than 25 degrees over the last 24 hours, indicating an eruption could be imminent.

Despite the danger, authorities said 25,000 people were ignoring evacuation orders and remained in the danger zone around Kelud. There was no attempt made to stop people from traveling inside a 10-kilometer (6-mile) zone around the peak that officials said is off-limits.

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"They believe it will not erupt," said Sigit Raharjo, a spokesman for the local government close to the mountain in the heart of the country's densely populated Java island. "They are being very foolish. All we can do is ask them to leave."

Kelud — one of more than 100 active volcanos in Indonesia — has been on the highest alert level for more than two weeks, but on Saturday recorded a spike in activity that led scientists to wrongly declare an eruption had begun.

Scores of people, including women carrying babies in slings, fled the mountain in police trucks and on bicycles and motorcycles to government buildings and tent camps, but on Sunday there appeared to be little sense of panic on the mountain.

"If I live in a shelter, I can't make money," said Buhirin, a 74-year-old farmer living well within the danger zone. "I have the courage to stay because I have experienced three Kelud eruptions. I know where the lahar (flows of mud and hot water expelled from the crater) will flow."

Scientists fear the buildup of magma under Kelud's lake could trigger a violent blast, sending a torrent of mud, ash and rock pouring down the side of the 1,731-meter (5,679-foot) mountain.

On Saturday, the peak recorded nonstop volcanic tremors as well as a surge in temperature in its lake. Monitors fled their observation posts convinced an eruption had begun, but were unable to visually confirm it because the mountain was shrouded in fog. They later said it had not erupted.

Surono, the lead scientist monitoring Kelud, said the extreme heat in the lake was creating a cloud of smoke and steam some 500 meters (1,640 feet) high, but Kelud had not erupted and no ash had been emitted. The smoke was briefly visible soon after dawn, but was then obscured by low cloud and heavy rain. Like many Indonesians, Surono goes by a single name.

In 1990, Mount Kelud killed more than 30 people and injured hundreds. In 1919, a powerful explosion that could be heard hundreds of kilometers (miles) away destroyed dozens of villages and killed at least 5,160.

For weeks, authorities have pleaded with villagers to move to tent camps or government buildings, but have faced resistance. Many people have insisted on staying behind to tend crops or look after their houses.

Some apparently believe a local myth that the mountain won't erupt if residents turn off all the lights and speak softly.

Indonesia is spread across 17,500 islands and is prone to volcanic eruptions and earthquakes because of its location within the so-called "Ring of Fire" — a series of fault lines stretching from the Western Hemisphere through Japan and Southeast Asia.

At least three volcanoes are currently erupting elsewhere in the country, including Mount Anak Krakatau, which lies off the northern tip of Java island. The mountain was formed after the famous Krakatau volcano erupted in 1883, killing thousands, but is not seen as at risk of a major blast.