The attack on Monday evening came as the UN Security Council prepared to decide on extending the mandate of a peacekeeping mission in Darfur, where tens of thousands have been killed in a 13-year conflict.
On Monday, gunmen "burned and looted" a camp for displaced people in Thur in the state of Central Darfur, said the African Union-United Nations force, UNAMID.
"The incident has reportedly resulted in four people being killed and seven others injured," it said.
A tribal leader from the camp, Sheikh Abdalraz Youssef, said the dead included a child.
"Militiamen attacked the camp and started shooting on the residents," Youssef told AFP by telephone.
Darfur has been gripped by conflict since 2003, when ethnic minority rebels rose up against the Arab-dominated regime of President Omar al-Bashir, accusing it of discrimination.
Bashir launched a brutal counterinsurgency and at least 300,000 people have been killed, the United Nations says. Another 2.5 million have fled their homes.
Bashir is wanted by the International Criminal Court on war crimes charges related to Darfur, which he denies.
Khartoum insists the conflict has ended, although violence occurs regularly.
In May, Arab tribesmen shot dead eight ethnic minority villagers as they prayed in a mosque in West Darfur.
In April, as many as 20 people were killed in clashes between two rival Arab tribes in East Darfur sparked by livestock thefts.
The Security Council is expected to meet before the end of June to decide whether to extend UNAMID's mandate by another year to June 30, 2017.
Khartoum wants a complete exit of UNAMID from Darfur, but a special UN report has recommended keeping the force in place.
The report cites the "limited progress" made to reach a viable solution to end the conflict in Darfur.
About 20,000 troops and policemen from more than 30 countries are currently in Darfur, a region of the size of France.
One of the camps for the dispalced in Darfur
Gunmen shot dead four people at a camp for displaced people in Sudan's war-torn Darfur, the United Nations peacekeeping mission said on Wednesday.
