JAKARTA - Indonesia's Sinabung volcano in northern Sumatra province erupted again on Wednesday (Dec 27), sending hot clouds into the sky.

The eruption occurred at 3.36pm local time, the country's disaster management agency (BNPB) spokesman Sutopo Purwo Nugroho said in an update on his Twitter account.

The eruption sent black gray volcanic ash up into the sky as high as 3,500m towards the east and south-east and 4,600m in the south and south-east direction.

Volcanic ash also fell on several villages around the volcano, he said.

There were no casualties from Wednesday's eruption as those living within the red zone around the volcano had been evacuated, he added.

"Mount Sinabung's continuous eruptions have caused the exclusion zone to expand," Dr Sutopo said, adding that 3,331 families who live in areas prone to the impact from the eruptions must be evacuated.

"Residents need to stay alert and listen to the government's recommendations. We cannot predict when Mount Sinabung will stop erupting. Mount Sinabung's volcanic and seismic parameters are still high therefore future eruptions are still likely."

The eruption on Wednesday followed another on Dec 18.

The Indonesian authorities have imposed the highest alert on the volcano, which has been in place since 2013 when it began erupting.

Gunung Sinabung kembali meletus pada 27/12/2017 pukul 15.36 Wib. Letusan disertai awan panas guguran dengan jarak luncur 3500 m ke arah Tenggara-Timur dan 4600 m ke arah Selatan-Tenggara. Hujan abu vulkanik turun di beberapa desa di sekitar Gunung Sinabung. pic.twitter.com/Z9AcNI7Ar9 — Sutopo Purwo Nugroho (@Sutopo_PN) December 27, 2017