A leading human rights group has accused the Sudanese military of indiscriminately bombing villages in rebel-held regions of Darfur.
The New York-based Human Rights Watch said witnesses in north Darfur reported that Sudanese military aircraft targeted general areas, which often destroyed people's homes.
Sudan has said it would send some 10,000 troops to Darfur, in the west of the country, to fight rebel groups that had not signed a peace agreement with the government in May.
"Government forces are bombing villages with blatant disregard for civilian lives," said Peter Takirambudde, Africa director at Human Rights Watch. "A penalty for indiscriminate bombing in Darfur is UN Security Council sanctions, which should be imposed now."
He said witnesses reported flight crews rolling bombs out the back ramps of Antonovs, a means of targeting practiced by government forces in their 21-year civil war with rebels in southern Sudan.
"This method is so inaccurate that it cannot strike at military targets without a substantial risk of harm to civilians," Human Rights Watch said.
"Deliberately attacking civilians is in all circumstances prohibited and a war crime," it added.
The Darfur conflict erupted in February 2003 when non-Arab rebels took up arms against the government. In response, the government mobilised Arab militias known as Janjaweed, who have been accused of murder, rape and looting.
In the past few months, various rebel groups and bandits have committed similar atrocities. Fighting, disease and hunger have killed some 200,000 people and driven some 2.5 million into squalid camps.
Sudan has so far rejected a UN Security Council resolution calling for the creation of a UN peacekeeping force in Darfur.