An Arab militia firing heavy machine guns killed more than 50 people in Sudan's Darfur region on Saturday, residents said, continuing unrest that has caused the largest displacement of people in years.
"They came on Land Cruisers, used Dushkas and they burned 30 houses killing 53 people," said one resident of El Sireaf town, to which most of the 100,000 people displaced or severely affected by the earlier tribal fighting had fled.
Another resident, who said he was wounded, also gave a figure of 53 dead.
The two said the attackers wore uniforms and belonged to a militia of the Rezeigat tribe, which has been fighting rival Arabs from the Beni Hussein group since early January in the Jebel Amir gold mining area of North Darfur state.
"We are in the cemetery burying these people," the first resident said, adding that the dead included two women and two children.
The second said he had been wounded in the leg and when he went to the town's hospital he found it filled with others who had been hurt in the attack.
"Some of them are waiting outside under trees," he said.
Both residents asked not to be identified. They said the victims were members of the Beni Hussein tribe.
A Rezeigat source said he heard there had been "tension" but did not immediately have details.
Officials at the African Union-UN peacekeeping mission in Darfur (UNAMID) could not be reached for comment.
The violence illustrates the changed nature of Darfur's conflict, where 10 years ago on Tuesday rebels from black tribes began an insurrection against the Arab-dominated Khartoum regime.
Darfur's top official, Eltigani Seisi, told AFP last week "the major issue" in Darfur now is not rebel attacks but "ethnic violence" such as that in Jebel Amir.
He admitted that government-linked militia in North Darfur have "committed atrocities against innocent civilians" but he said they are to be disbanded under a peace deal reached with rebel splinter factions.
Darfur's major rebel groups rejected the peace deal signed two years ago in Qatar.
Generally the security situation "has improved a lot" in Darfur, Seisi said.
In late January, Amnesty International said Sudanese security officers were reportedly involved in the initial Jebel Amir attacks that killed up to 200 people.
Fighting began when a Rezeigat leader, who is an officer in Sudan's Border Guard force, apparently laid claim to a gold-rich area in Beni Hussein territory, Amnesty said.
"Gunmen driving government vehicles are alleged to have opened fire on people in the mostly Beni Hussein area of Kebkabiya using grenades and heavy machineguns," Amnesty said.
"These events come as the government is attempting to exert greater control over licensing and export of gold, in a context of fiscal crisis, depleted foreign exchange reserves and widespread gold smuggling," it added.
A humanitarian source told AFP the Beni Hussein had refused to pay newly imposed government mining fees adding up to "huge, huge money".
Before the Jebel Amir unrest more than one million people were already living in camps for the displaced in Darfur.
Elsewhere, four civilians were killed and 37 wounded when Sudan's air force bombed on Thursday Derib al Reih village in South Darfur state, a rights group said in a statement received Saturday.
The African Centre for Justice and Peace Studies gave the names of the victims, two 15-year-old students, a man and a woman and said that "over 150 families from the community were displaced by the attacks.
A local resident told AFP that he attended the burial of the four victims, who were killed southeast of the state capital Nyala.
Rebels said they had fought with government troops near Nyala's southern outskirts on Thursday.
The army could not be reached but Sudan last week denied conducting air raids in Darfur.