Tens of thousands of people have been evacuated from villages near the volcano [AFP]

At least two more people have been killed after Indonesia's Mount Merapi erupted for the second time this week, spewing vast clouds of ash and sparking chaotic evacuations in the central Java province.

The deaths on Saturday occurred as hundreds of soldiers, police and locals, who feared a repeat of Tuesday's eruption that killed 36 people and displaced about 50,000 others, fled from their homes. 

"A total of 38 people have been killed because of burn injuries and accidents since the 26th. Two of them, an adult woman and a one year-old boy, died because of accidents," Arif Novianto, a local hospital spokesman, said.

According to witnesses, at least two others were taken to hospital on Saturday with injuries from breathing in the hot ash.

Loud explosion

Residents in the province said the explosion at around 18:00 GMT on Friday was louder and stronger than the earlier eruption.

"My neighbours told me to leave and my village is already empty, everyone has fled," Mukinem, a resident who was heading away from the volcano on a motorcycle with her husband and two young children, said.

"I heard several sounds like thunder. I was so scared I was shaking," she said.

A resident of Hargobinangun, just outside the 10-kilometre exclusion zone established by the government, said the eruption was "more than twice as big as the first eruption on Tuesday".

Subandrio, a local volcanologist, said the new eruption was another reminder that Mount Merapi, remained "extremely dangerous".

He said the government had to be "more serious" about enforcing the exclusion zone amid persistent reports of people leaving displacement camps to tend to their livestock on the mountain's slopes.

"We will even have to evaluate whether we need to widen the exclusion zone because we should not downplay the threat - Mount Merapi is extremely dangerous," he said.

But he also said the impact was not as great as that of the previous eruption.

More than 50,000 people are living in temporary shelters near the central Java city of Yogyakarta after being ordered to evacuate on Monday.

"It was big but not as big as the one on Tuesday in terms of the volume of volcanic material which was thrown out," he said.

Mount Merapi, which means "Mountain  of Fire", is the most active of the 69 volcanoes with histories of  eruptions in Indonesia.

Source: Agencies