A Sudanese air force bombardment of villagers in Darfur this week killed or wounded almost 100 people, a U.N. spokeswoman said Friday, calling the bombing a major violation of a fragile ceasefire in the conflict-torn region.

The bombardment at the village of Shangil Tobaya (search), which took place Wednesday, forced "thousands" of people to flee, spokeswoman Radhia Achouri said in a phone interview from Khartoum (search).

Achouri said African Union (search) observers at the scene had reported "almost 100 casualties" but did not specify how many were dead and how many wounded.

"But 100 casualties is 100 too many, be they wounded or dead," she said. "It is definitely one of the most serious violations of the cease-fire" signed by the government and the Darfur rebels last year.

The United Nations mission in Khartoum spoke to Sudan's Foreign Ministry about the bombardment, but has received no reply.

NGO field workers based in Shangil Tobaya, 40 miles south of El Fasher, reported witnessing bombs exploding on the ground and an air force Antonov circling overhead on Wednesday afternoon.

Later the same day, the African Union, which has 1,400 cease-fire monitors and protection troops in Darfur, confirmed there was an aerial bombardment and called it a "major violation" of the cease-fire.

The Sudanese government has issued no statement on the report. On Thursday its deputy information minister declined to comment, saying a call from The Associated Press was the first he had heard of the matter and he was on vacation.

"The Government of Sudan always says aerial bombardments are not government policy and that President Omar el-Bashir has issued firm instructions that there should be no use of Antonovs for aerial bombardment," Achouri said.

The Sudanese government has often been accused of employing its air force against civilians in Darfur, and it has usually denied the allegations. It is rare that an aerial bombardment is confirmed by the African Union.

The Darfur conflict, which the United Nations describes as the world's worst humanitarian crisis, began in February 2003 when the Sudan Liberation Army (search) and allied Justice and Equality Movement (search) took up arms against what they saw as years of state neglect and discrimination against Sudanese of African origin.

The government responded with a counterinsurgency campaign in which the Janjaweed (search), an Arab militia, committed wide-scale abuses against the African population. An estimated 1.8 million people have been displaced in the conflict.