KHARTOUM, Sudan - More than 200 people have died in clashes between ethnic African farmers and nomadic Arabs in South Darfur in the past week, leading the Sudanese government to send emissaries to try to reconcile the tribes involved, officials said Saturday.

The fighting was the latest outburst in a nearly four-year-long conflict that has caused more than 200,000 deaths and chased 2.5 million people from their homes in Sudan's vast Darfur region, where nomadic tribes and farming communities have long wrangled over access to scarce water.

The war began when ethnic African rebels took up arms against the Arab-dominated government in February 2003, charging it with neglect. The Khartoum regime is accused of responding by unleashing Arab paramilitary groups known as janjaweed that have been blamed for the worst atrocities in the conflict. The Sudanese government rejects the allegations.

The latest fighting involved Habania Arab nomads and Falata ethnic African farmers, Justice Minister Mohammed Ali Al Mardhi told the independent newspaper Al-Rai al-Amm. He said more than 200 people had been killed over the past week, mainly nomads, and that the government had sent reconciliation missions to try to end the fighting.

"The situation between the two sides remains flammable," he said.

Witnesses who spoke on condition anonymity for fear of reprisals said the clashes began a week ago in an area south of Nyala when Habania nomads killed nine Falata tribesmen they accused of stealing cows. Habania fighters later attacked a Falata settlement but suffered heavy casualties, the witnesses said.

Sudanese Interior Minister Zubair Bashir Taha appealed to tribal leaders to stop the killing and "resort to the voice of wisdom," the state-run SUNA news agency said.

The government's casualty estimate could not be independently verified, because the government has barred foreign journalists from Darfur for months.

The African Union peacekeeping mission deployed in Darfur said it had not investigated the violence. "But we encourage reconciliation missions to avoid this kind of fighting over resources," AU spokesman Noureddine Mezni said.

He said the AU was also aware of separate clashes between other tribes of nomads and farmers that killed 42 people elsewhere in Darfur earlier in the week, according to Sudanese media.

Some 7,000 AU peacekeepers have struggled to maintain a cease-fire in Darfur since the government and one of the rebel groups signed a peace agreement last May. Khartoum has opposed a U.N. Security Council effort to take over command of the peacekeeping force and bring in 20,000 U.N. soldiers and police.

Sudan is geographically the largest country in Africa and its population is composed of dozens of tribes deeply divided by language, religion and ways of life. There have been separate ethnic African rebellions in the country's east, south and west.

Former southern rebels signed a peace agreement with the government in 2005, but that region remains volatile. The U.N. World Food Program said one of its employees was killed in an ambush there on Wednesday.