International flights to Jakarta returned to normal Monday after ash clouds from Indonesia's most active volcano caused a weekend of travel chaos ahead of a visit by US President Barack Obama.

The toll from a series of eruptions of Mount Merapi over the past two weeks rose to 141 on Monday as bodies were pulled from the sludge that incinerated villages on Friday, the volcano's biggest blast since the 1870s.

The latest eruption forced airlines to cancel 44 flights at the weekend, but officials said there would be no repeat of events in Iceland this year when a volcano disrupted transport across Europe.

"Everything has returned to normal today," Air Transport's director general Herry Bakti told AFP, referring to flights in and out of Soekarno Hatta international airport in Jakarta.

Obama is scheduled to arrive in Jakarta on Tuesday for a highly anticipated - and twice delayed - visit and US embassy spokesman Paul Belmont said the trip "will go ahead as planned".

Merapi lies 430 kilometres (270 miles) east of Jakarta but only 26 kilometres north of Yogyakarta, the historic capital of Central Java province, where the airport was closed for a fourth day on Monday.

Rescuers said Monday they found six bodies, including those of four rescuers, in Glagaharjo village about 10 kilometres from the mountain.

"We found the bodies of two villagers and four rescuers today. They were charred beyond recognition. The rescuers were killed while trying to save victims," rescue worker Anwar said.

Friday's eruption killed at least 97 people and destroyed villages up to 18 kilometres away.

More than 278,000 people are living in cramped temporary shelters after being ordered to evacuate from a 20-kilometre "danger zone".

Government vulcanologist Surono said gas and ash soared four kilometres into the air on Monday as the volcano, a sacred landmark in Javanese tradition, continued to heave and rumble.

"Merapi hasn't stopped erupting since November 3. It's been fluctuating but tends to be in the high intensity range," he said.

Indonesia's most-visited tourist site, the ancient Borobudur temple about 40 kilometres southwest of the volcano, was closed for a fourth day.

"The ash is two centimetres (one inch) thick... We're worried that the temple's statues could be damaged by this material," temple official Iskandar said.

Disaster management agency spokesman Sutopo Purwo Nugroho warned of potential flooding after volcanic debris known as lahar flowed into the Code River in Yogyakarta on Saturday.

"One of our concerns is potential flooding due to the flow of lahar. We've asked residents living close to 12 rivers around Merapi to be more vigilant as there's a chance that might happen," he said.

The Indonesian archipelago has dozens of active volcanoes and straddles major tectonic fault lines known as the "ring of fire" from the Indian to the Pacific oceans.

The authorities are also dealing with the aftermath of a tsunami which smashed into villages on the remote Mentawai island chain on October 25, killing over 400 people.