Wadi Anka, Sudan Ahmad Salaheddin is an Arab who has crossed the ethnic divide in Darfur's bloody war to fight alongside ethnic African rebels. His fellow rebels jokingly call him a "janjaweed" - one of the Arab militiamen who are their fiercest enemy.
His presence, along with several other Arabs in a unit of the main rebel group in Darfur, the Sudan Liberation Army, is a sign of the complexity of the ethnic bloodshed in the western Sudanese region.
The fight in Darfur is usually defined as between Arabs and ethnic Africans: the ethnic Africans launched a rebellion in 2003 and the Arab-led Sudanese government is accused of arming Arab tribesmen in Darfur to help put it down.
The Arab janjaweed militias have since carried out a campaign of violence against ethnic African civilians, killing and raping and driving hundreds of thousands from their homes, the United Nations says.
In general, the definition of Arabs vs. ethnic Africans holds true. It is not known how many Arabs have joined the ethnic African rebels, but their numbers are likely minimal. However, the rebels insist instances like Salaheddin are on the rise.
There are also several major Arab tribes that from the start have refused Khartoum's enticements to join the janjaweed. So the government has armed smaller, more impoverished clans for the militias - disrupting the traditional power structures among the Arab tribes.
In a reflection of the turmoil, infighting and violence among Darfur Arabs has surged in recent months, killing hundreds.
Another complication is that the regular government troops in Darfur fighting the rebellion are mainly ethnic African draftees from other parts of Sudan. The rebels say they do not fear those government troops as much, because they are not enthusiastic fighters and are easier to combat than the janjaweed.
Salaheddin said he joined the mostly African rebels because he was angered at Darfur's underdevelopment and believes the Khartoum government is manipulating Arabs in Darfur.
"They don't care about us any more than they care about the Africans," he told The Associated Press. "In fact, our conditions here are just as bad."
Arab and ethnic African tribes have long competed for scarce resources in Darfur, a vast, semiarid region of western Sudan nearly the size of Texas. There were troubles even before ethnic Africans launched their rebellion, complaining of discrimination at the hands of Khartoum.
But there were also neighborly relations, tightened sometimes by intermarriage.
Saleh Ibrahim - an SLA fighter from the African Zaghawa tribe, which spearheaded the rebellion - pointed to his relatively lighter skin and noted that his grandmother was an Arab. But he said all ties had been cut with his Arab cousins since the rebellion began, and that he didn't know their whereabouts.
"It's sad, because we used to get along quite well," he said. "I don't think it would be possible anymore ... Too much blood has been spilled."
The Arab-dominated Sudanese central government in Khartoum denies controlling the janjaweed, whom it describes as bandits. But the International Criminal Court last month accused a senior government official and a janjaweed leader of crimes against humanity and said their campaign was coordinated.
Overall, more than 200,000 people in Darfur have been killed since 2003, and more than 2.5 million people, largely African villagers, now live in massive refugee camps scattered across Darfur and spilling over into neighboring Chad.