Khartoum - Tribal violence and rebel-government battles have displaced at least 460 000 people in Sudan's Darfur this year, the United Nations said on Thursday, as violence worsens in the western region.
"According to humanitarian organisations, so far in 2013 at least 460 000 people have fled their homes in Darfur as a result of inter-tribal fighting and clashes between the SAF [Sudanese army] and armed movements," the UN Office for the Co-ordination of Humanitarian Affairs (OCHA) said in its weekly bulletin.
"This is more than the number of people internally displaced in Darfur in 2011 and 2012 combined."
The latest figure marks a jump from the 300 000 who UN humanitarian aid chief Valerie Amos announced in May had been displaced during the first five months of the year.
Tribal violence has eclipsed rebel activity as Darfur's major security threat, Defence Minister Abdelrahim Mohammed Hussein said in a briefing to parliament on Tuesday.
In the latest tribal fighting, Arab militias used rockets, artillery and heavy machine guns in battle across a wide swathe of southwest Darfur on Sunday, sources in the warring Taisha and Salamat tribes told AFP.
Non-Arab rebels rose up 10 years ago in Darfur, seeking an end to what they viewed as Arab elites' domination of Sudan's power and wealth.
In response, government-backed Janjaweed militiamen shocked the world with atrocities against civilians.
Analysts say the cash-starved government can no longer control its former Arab tribal allies, whom it armed against the rebellion, and violent competition for resources has intensified.
Darfur's top official, Eltigani Seisi, said in late October that tribal forces have become so strong that they "are now beyond control of the tribal leaders".
He said the government's security forces need to be strengthened, but disarmament of the militias can only come in conjunction with a laying down of arms by the rebel groups.
The defence minister told parliament that his forces were commencing an operation to crush the rebels in Darfur as well as other insurgents in South Kordofan state over the next few months.
Darfur rebels are joined in the Sudan Revolutionary Front alliance with insurgents from the Sudan People's Liberation Army-North (SPLA-N), who have been fighting for two years in South Kordofan and Blue Nile states.
The Revolutionary Front seeks to topple the Khartoum regime and install a government more representative of the country's diversity.
President Omar al-Bashir and his defence minister are both wanted by the Hague-based International Criminal Court for alleged war crimes in Darfur.