SIDOARJO, Indonesia.- To Indonesia's recent natural disasters -- tsunamis, volcano eruptions and the earthquakes -- add a man-made one: the mud volcano eruption of Sidoarjo.

On May 29, two days after an earthquake wrecked Indonesia's cultural capital, Yogyakarta, villagers in Sidoarjo, 200 miles away, were overwhelmed by the smell of rotten eggs.

Soon after, a geyser of toxic gas, superheated water and mud began boiling out of a natural gas exploration hole. Pouring out at a rate of about 3.5 million cubic feet a day, the sludge eventually covered 12 villages, 15 factories and miles of rice fields.

The mud, which continues to pour out at an accelerating rate, has left 13 persons dead and more than 15,000 homeless and seeking compensation. The government last week announced that it was diverting rail traffic in the area because the river of mud had engulfed a railway line.

A team of mud volcano researchers from British universities concluded in January that the eruption probably started when a gas exploration drill punched through a layer of rock 9,000 feet below the surface, allowing the pressurized steam, mud and water to escape to the surface.

"We cannot be absolutely certain ... but I would say that the chances that it was caused by drilling are probably in excess of 90 percent," said Richard Davies, one of the world's foremost scientists on mud volcanoes and a lead author of the report from Durham University in Britain.

"There is a lot of drilling evidence to support this conclusion. The evidence for it occurring due to an earthquake is very weak and not supported by scientists."

Agnes Tuti, a researcher and social scientist at the University of Surabaya, said the gas company had been warned of the risk but ignored the advice.

"The leak was a deliberate inaction [by] the responsible company," Miss Tuti said. "PT Lapindo Brantas was warned by an American drilling company not to drill. But it decided to drill anyway, to use a protective shield. They ignored the warnings and do not want to take responsibility."

PT Lapindo Brantas is run by a brother of Indonesia's minister of welfare, Aburizal Bakrie, who financed the president's election campaign. The minister and PT Lapindo Brantas blame the disaster on the earthquake.

But the government has declared a state of emergency, blaming the company for what is being called the greatest man-made disaster ever in East Java. The government is seeking $440 million in damages, including $300 million to compensate the victims.

The company is trying to fill the mouth of the mudhole with chains of concrete balls, each weighing about 175 pounds. Most scientists say that it is probably a waste of time.