U.N. Secretary-General Kofi Annan told the U.N. Human Rights Council on Tuesday to immediately address the escalating atrocities in Darfur by sending an independent team of investigators to the volatile Sudanese region.

"It is urgent that we take action to prevent further violations, including by bringing to account those responsible for the numerous crimes that have already been committed," Annan said in a recorded video address to open the 47-nation council's emergency session on Darfur.

Even though African countries have indicated "concern" over rights abuses resulting from the three-year-old conflict, they have opposed a European attempt to send independent fact-finders. Instead, they have proposed to send diplomats.

"I urge you to lose no time in sending a team of independent and universally respected experts to investigate the latest escalation of abuses," Annan said.

It has taken six months to get the new body to deal with accusations that the Sudanese government is involved in atrocities that include rapes and slayings of civilians, destruction of villages and mass flight.

Instead the council has used its previous three full sessions and three special sessions to pass eight resolutions denouncing Israeli treatment of Arabs. No other country has been singled out for criticism.

"The unrelenting tragedy in Darfur demands the commensurate engagement and vigilance of the Human Rights Council," said Louise Arbour, the United Nations' top human rights official.

She cited "credible evidence" that Khartoum was upgrading the arsenals and mobility of militias accused of the worst atrocities.

"The desperate plight of the people of Darfur has for too long been neglected or addressed with what the victims should rightly regard, and history will judge, as meek offerings, broken promises, and disregard," Arbour said.

The deputy governor of South Darfur, Dr. Farah Mustafa, rejected the accusations saying that the situation was being "ill-represented and distorted," and that it should not be exploited for hidden political agendas.

He also accused the high commissioner of lacking impartiality.

"The international media and the office of the high commissioner have coordinated pressure on the government (of Sudan) so that it give its consent to international troops," Farah said. The council should rather support the existing peace agreements and the African Union troops, he added.

The Sudanese government has repeatedly rejected a U.N. proposal to replace an underfunded, undermanned AU peacekeeping force in Sudan with a larger force that could combine the U.N. and the African Union.

The Sudanese government is accused of unleashing the janjaweed militia to help counter ethnic African groups who rebelled in 2003. More than 200,000 people have been killed and some 2.5 million people have fled their homes in the violence, according to U.N. estimates.

Numerous aid workers have had to leave Darfur because of insecurity and militia attacks.

Khartoum denies backing the janjaweed, but agreed to disarm them as part of a peace agreement it signed with one Darfur rebel group in May.

In one of the latest recent incidents of violence, an estimated 30 civilians were killed Sunday by militia members who ambushed a civilian truck between the towns of Geneina and Sirba in western Darfur.

The U.N.'s top humanitarian official Jan Egeland said last week the Darfur conflict has spread into neighboring Chad and the Central African Republic and was in "free fall," with the prospect of 6 million people in a hopeless situation without food or protection.

The outcome of the special session will be measured by the composition of the fact-finding mission. A resolution put forward by the 13-member African group within the council proposes sending diplomats. The European Union has drafted a counter-resolution to send independent human rights experts.

Rights groups have warned that a diplomatic mission would be easier to influence, and have pointed to Sudan's repeated invitation of ambassadors from council member nations on what Egeland described as "guided tours."

Resolutions by the rights council are nonbinding, but increase political pressure on criticized countries.

The council replaced the widely discredited Human Rights Commission in June.