According to the state-run Sudanese news agency Suna, at least 1,700 people have crossed into Sudan as a result of fighting between armed factions in South Sudan's northern Upper Nile province.

Earlier reports of escalating civilian casualties, injuries, and kidnappings prompted thousands of women and children to evacuate their homes in Upper Nile state as a result of fighting between armed factions that began in August, according to the UN agency Unicef.

Since then, the fighting has spread to the states of Jonglei and Unity.

The UN reported on Wednesday that at least 166 people have died as a result of the violence.

Large numbers of South Sudanese fleeing the violence had arrived in the border state of White Nile, according to Salah Taaj al-Sir, a member of Sudan's state-run Humanitarian Aid Commission, who spoke to Suna.

He urged humanitarian organizations to help the refugees right away.