At least 22 Sudanese children drowned on Wednesday when their boat sank in the Nile while they were on their way to school, official media said.

A woman also died when the vessel went down around 750 kilometres (470 miles) north of the capital Khartoum with more than 40 children on board, the SUNA news agency reported.

Civil defence forces are searching the waters for the bodies of the missing children, the agency added.

The Nile River is seen after heavy rainfall in the Sudanese capital Khartoum in August 2016

It said the boat's engine failed in a high current while it was crossing the river to reach a school in Kabna, a small village in northern Sudan.

Villagers in the region rely on wooden boats to cross the Nile.

A witness told AFP by telephone that the boat had been crossing the river against the current.

'All the families (in the area) are in mourning,' added the witness, who did not want to be named.

The woman who died was identified as a hospital employee in the village.