United Nations: The Security Council has extended its peacekeeping mission in Abyei, a region contested by Sudan and South Sudan, and demanded that Sudan withdraw a platoon of police troopers from an oil refinery in the area.

The council on Friday unanimously agreed to keep the Ethiopian-led force of almost 4,000 in the field for another six months.

Secretary-General Ban Ki-moon recommended the extension, saying in a recent report that the region has been relatively calm for several months, but Sudan and South Sudan have made scant progress in settling border disputes.

The force, dubbed UNISFA, was deployed to monitor and verify the withdrawal of Sudan’s army and South Sudan forces from Abyei, help establish a demilitarized zone and mark the disputed border, and establish a regional police force to provide security. It also assists in the delivery of humanitarian aid and protects UN and humanitarian workers.

Troops have been withdrawn, but Sudan maintains some 120 to 150 “oil police” from the oil complex at Diffra in northern Abyei. The oil police don’t conduct operations outside the refinery, but their presence violates prior Security Council resolutions, and the council on Friday demanded their withdrawal.

The Security Council expressed its concern over delays in setting up a civil administration and police force for the region to replace troops from Sudan and South Sudan.

Sudan and South Sudan have nearly gone to war since South Sudan gained independence in June 2011, and Sudan has fought to suppress various rebel insurgencies for decades.

The relative calm in Abyei contrasts with ongoing Sudanese aerial bombings and clashes with rebel forces in other border states.

The office of the UN High Commissioner for Refugees on Friday reported a sharp rise in new arrivals at South Sudan’s largest refugee camp due to escalating fighting in the South Kordofan region of neighboring Sudan.

As of last week, there were 175,668 Sudanese refugees in South Sudan from fighting and insecurity in South Kordofan and Blue Nile states in Sudan. Almost half of these are from Blue Nile. Fighting also flares in Darfur.

Since September, thousands of people have been prompted to flee South Kordofan into Yida as a result of renewed fighting between Sudanese military and the rebel group known as the Sudan People’s Liberation Army (SPLA-North).

In July, the council extended its peacekeeping mission in South Sudan for another year, in a resolution that called on the young nation to take more responsibility for protecting its civilians. That mission, known as UNMISS, is a force of more than 5,000 troops and hundreds of police and UN civilian staff that were sent to protect civilians and help improve security.