Ash blankets town near Indonesian volcano

"We have checked with the volcano monitoring team, and they say that the ash does not come from Kelud, but from Semeru," he told AFP, referring to a volcano about 90 kilometres (55 miles) away.

Semeru has been spewing ash on and off for months, scientists saying that the volcano's activities were still considered normal and not dangerous.

Meanwhile scientists said they were baffled by the behaviour of Kelud, with the energy surging inside it surpassing that of its last eruption, in 1990.

Scientists abandoned their monitoring posts on Kelut's slopes on Saturday when tremors became so strong they could no longer be measured. They could not see the peak through heavy cloud but said they believed it was erupting.