The UN Security Council has extended the mandate of an international peacekeeping force in Darfur for a year despite fierce opposition from the Sudanese government.

On Wednesday, the Security Council extended the mandate of the UN-African Union Mission in Darfur (UNAMID) to June 30 next year, saying that the situation in Sudan threatened global peace and security.

About 18,000 troops and police from more than 30 countries will continue to deploy as part of the peacekeeping mission in Darfur, a region the size of France where tens of thousands of civilians have been killed since 2003.

The UNAMID mission was first deployed in Darfur in 2007, a compromise between Western calls for a fully-fledged UN peacekeeping mission and Khartoum’s insistence on an African solution.

The Security Council decided to extend its mandate after "determining that the situation in Sudan constitutes a threat to international peace and security,” said the resolution adopted on Wednesday.

The extension had been recommended in a report by UN chief Ban Ki-moon and African Union Commission chairperson Nkosazana Dlamini Zuma.

In the run-up to the vote, Khartoum had expressed stiff opposition.

Last month, Minister of State for Foreign Affairs Kamal Ismail said: "It’s time to say goodbye to the UNAMID mission.”

Khartoum insists that unrest in Darfur has ended, and that an April referendum in Darfur -- boycotted by the opposition and widely criticised by the international community -- had "turned a page” on the conflict.

Officials said almost 98 per cent of voters opted to maintain Darfur as five separate states, not the single region favoured by the opposition.

Violence erupted in Darfur when ethnic minority rebels rose up against President Omar al-Bashir, accusing his Arab-dominated government of marginalising the region.

Bashir mounted a brutal counter-insurgency and at least 300,000 people have been killed in the conflict, the UN says. Another 2.5 million have fled their homes.

The Security Council said that Darfur remains prey to insecurity.

It said Darfur continued to witness attacks by rebel groups and government forces in the central Jebel Marra highlands, inter-tribal fighting, banditry and crime.

It said "sexual and gender-based violence targeting women and girls” also affected the region.

The Security Council noted that 80,000 people fled their homes in the first five months of the year adding to hundreds of thousands of displaced people already living in camps.

"The continued denial of access and restrictions imposed on humanitarian actors have left significant gaps in the delivery of humanitarian assistance,” it said.

There have been persistent reports of violence in recent months.

Earlier this month, gunmen killed four people at a camp for displaced people in Central Darfur.

In May, Arab tribesmen shot dead eight ethnic minority villagers as they prayed, in a revenge killing in West Darfur.

And, in April, as many as 20 people were killed in clashes between rival Arab tribes in East Darfur sparked by cattle rustling.