Seventy patients and companions died in a drone strike on one of the last functioning hospitals in western Sudan's Darfur, the region's governor said.

The head of the World Health Organization called on Saturday for an end to attacks on healthcare workers and facilities in Sudan after a drone attack on a hospital in Sudan's North Darfur region killed more than 70 people and wounded dozens.

The unmanned aircraft carrying explosive warheads are part of a Ukrainian campaign of long-range drone attacks that aim to inflict blows on Russia far behind the front line as Moscow's troops advance in the east.