This is the shocking moment a school building collapsed into a river as heavy rains battered Indonesia.

Footage shows a two-storey student dormitory buckling before it crumbled into the nearby Batee Liek River in Bireuen Regency, Aceh province, on Wednesday morning.

The structure was reportedly part of the the Dayah Najmul Hidayah Al-Aziziyah Islamic boarding school complex situated on the riverbank.

Onlooker Muhammad Luthfi said: 'The landslide was caused by flooding from the Batee Iliek River. There were no casualties.

'Only a portion of the students' belongings could be saved. The students are temporarily taking refuge in the mosque at the Islamic boarding school complex.'

Local media reported that parts of Aceh province were flooded as monsoon rains battered the island of Sumatra.

Extreme weather has been lashing North Sumatra since November 24, triggering widespread flooding and landslides on the island.

Police today said at least 17 people were killed, while six others were missing. Many of the casualties were from the Tapanuli region.

Abdul Muhari, spokesman for the national disaster agency, said: 'In Tapanuli Selatan, the disaster of floods and landslides has resulted in eight people losing their lives, 58 being injured, and 2,851 residents had to evacuate.'

Joint teams were deployed to help trapped residents and deliver aid.

The local government urged the public to remain vigilant, as extreme weather was forecast to continue.

Indonesia and neighbouring countries in Southeast Asia are in their annual monsoon rainy season which sees soaring temperatures followed by powerful rain storms in the afternoon leading to widespread flash floods.