A young woman was killed in an "attack" by Sudan's counter-insurgency unit on a Darfur camp for displaced people, Amnesty International said on Tuesday, but authorities said she was shot in a clash.
Members from the pro-government Rapid Support Forces (RSF) on board five pick-up trucks and armed with machine guns on Monday attacked a camp for internally displaced people in Zalingei, the capital of Central Darfur State, the rights group said.
"A 22-year-old woman was shot in the head and later died in hospital," Amnesty said in a statement.
"Ten others, including children, sustained serious head, neck, arm and leg injuries," it said, adding that the reason for the shootings remained unclear.
The authorities in Central Darfur said the incident was the result of a "mistake".
"Six vehicles of RSF were travelling from South Darfur to Geneina in West Darfur when they mistakenly went inside an IDP camp on their way," a statement from the Central Darfur government said.
"The IDPs clashed with RSF after which the RSF troops fired in the air, and as a result of which one woman was critically injured."
Camp residents later demonstrated in front of the government building and clashed with security forces, the authorities said.
"Five soldiers and nine civilians were injured in these clashes," it said.
Amnesty International confirmed the demonstration and said seven people were arrested by security forces, including a student activist.
Amnesty urged the authorities to launch an impartial investigation into Monday's incident.
"The victims of this appalling attack were forced to flee from their homes by the violence that has plagued Darfur for years, and this camp was supposed to be a place of safety," it said.
The United Nations says that more than 2.5 million have been displaced since a deadly conflict erupted in Sudan's western region of Darfur in 2003. The conflict has killed about 300 000 people, the UN says.
An insurgency began in Darfur as rebels rose up against Sudan's government, accusing it of marginalisation.
Khartoum cracked down on rebels and insurgent groups have since fragmented, with fighting punctuated by periods of relative calm.
The level of violence has dropped across Darfur, with Khartoum insisting since last year that the conflict has ended.