International airlines were forced to reschedule dozens of flights to Indonesia on Sunday as deadly Mount Merapi spewed ash into the sky, ahead of a visit by US President Barack Obama.

Airlines cancelled eight flights on Sunday and 36 flights on Saturday, echoing disruption in Europe in April and May when ash from an Icelandic volcano caused transport chaos.

The toll from a series of eruptions since late October rose to 132 as bodies were pulled from the volcanic sludge that thundered down on central Java on Friday, Merapi's biggest eruption since the 1870s.

"Rescuers found more bodies in the villages. The victims had tried to escape the heat clouds but they were a little too late," Disaster Management Agency spokesman Sutopo Purwo Nugroho told AFP.

Mount Merapi began erupting on October 26 and Friday's blow-out killed at least 91 people, incinerating villages up to 18 kilometres (12 miles) away.

Jakarta airport official Frans Yosef said that in addition to the eight cancelled flights, 42 flights -- including by Singapore Airlines, Cathay Pacific and Malaysia Airlines -- had been rescheduled.

The volcano also disrupted flights to provincial capital Yogyakarta, Solo and Bandung, cities close to Merapi in the centre of the main island of Java. Thousands of passengers were stranded.

Malaysia Airlines resumed its morning and afternoon flights to Jakarta Sunday and is reinstating an evening flight to and from Jakarta "due to a forecast improvement" in the volcanic ash cloud, it said on its website.

A morning flight to Jakarta on Monday however would be cancelled, it added.

"Otherwise, all other flights to Jakarta on November 8 are expected to operate as usual," it said.

Air travellers grew increasingly frustrated.

"We called three airlines but all the seats were booked," said Singaporean Raymond Yong, 34, whose Lufthansa flight home from Jakarta was cancelled.

"I don't understand why the airlines have to cancel flights when there are others which are operating just fine. I have to work tomorrow and this is such a major inconvenience."

Three Malaysian Air Force Hercules C-130 transport aircraft flew to Yogyakarta to collect 664 Malaysians stranded there, in a series of flights to take place Saturday and Sunday.

Obama is scheduled to arrive in Jakarta on Tuesday for a highly anticipated -- and twice delayed -- visit.

US Embassy spokesman Paul Belmont said Sunday that Obama's schedule "will go ahead as planned". If the situation worsens, he said, "We'll cross the bridge when we come to it."

In Friday's eruption, fast-flowing torrents of boiling hot gas and rock -- known as pyroclastic flows -- killed people in their sleep, leaving smouldering ruins full of bodies.

More than 278,000 people are living in cramped temporary shelters after being ordered to evacuate from a 20-kilometre "danger zone", though many were reluctant to abandon their properties and livestock.

The volcano, considered a sacred landmark in Java, continued to spew gas and ash on Sunday.

It lies 430 kilometres (270 miles) east of Jakarta but only 26 kilometres north of Yogyakarta.

"The eruptions continue to pose a big threat to residents," volcanologist Budi Santoso said.

Hundreds of residents living on the banks of the Code river were urged to move at least 300 metres from the riverside as a "precautionary measure" after volcanic debris known as lahar flowed into the river on Saturday, Yogyakarta city spokesman Herman Edi Sulistio said.

More than 60 people people were buried in a mass grave in Margodadi village in Sleman district on Sunday, district spokesman Endah Sri Widiastuti told AFP.

"The site is about 30 kilometres away from Merapi's peak, it's well outside the 20-kilometre danger zone," she said.

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

The authorities are also dealing with the aftermath of an October 25 tsunami that killed more than 400 people.