UNITED NATIONS – International activists say that world leaders have played down events in Darfur, by sowing doubts about a deadly air attack last week, and, most significantly, underestimating the death count in the two-year war there.

A new study by a British doctor who has worked in Darfur and has a strong interest in epidemiology, Jan Coebergh, casts the often-cited number of 70,000 deaths in the region in doubt.

According to Mr. Coebergh’s analysis, posted on the Web site of the British Magazine Parliamentary Brief, www.thepolitician.org, the real number is much higher, closer to 300,000.

The January 26 air strike on innocent civilians in southern Darfur was quickly condemned internationally. But earlier this week the director of the U.N. African Division, Heile Menkerious, told the Security Council in a closed-door briefing that the African Union monitors on the ground could not verify that the attacking aircraft was government-owned.

One council diplomat who asked to remain unnamed told The New York Sun after the briefing that by now he was not even sure that the air attack even took place. But others were quick to point out that the U.N. special representative in Sudan, Jan Pronk, reported in a press briefing in Africa that he witnessed the aftermath of the attack.

The doubt sown by Mr. Menkerious was cited by representatives of human rights organizations as part of an emerging trend at the U.N. and among diplomats, who increasingly fashion a “moral equivalency” between the government and its proxy – Janjaweed militias on the one hand, and the much weaker Darfur rebels.

“The Sudanese government definitely carried out aerial bombings for the last six weeks, even though it has signed an agreement in November to stop air attacks,” a researcher at Human Rights Watch, Leslie Lefkow, told the Sun, adding that the government is the only power in there with an air force. Any attempt to belittle Khartoum’s responsibility is “off base,” she said.

Asked by the Sun whether moral equivalency exists, Secretary-General Annan said yesterday that the report prepared by his commission, which was delivered to the council earlier this week, concluded that atrocities were committed by both sides.

“Obviously the government is much bigger and with the Janjaweed has much larger resources,” he said. But the rebels, he added, “also committed atrocities, and I suspect there may be names of some rebels on the sealed list that the commission gave me.” That list was not opened by Mr. Annan, according to his spokesman, and it is intended for the use of future war crimes prosecutors.

In his council briefings and public statements, Mr. Pronk, who represents Mr. Annan in Sudan and regularly meets with Khartoum officials, has increasingly put blame on the rebel side. Last month, when asked about it by the Sun, he cited mostly rebel attacks on relief workers in Darfur.

Ms. Lefkow said that diplomats have had “a lot of investment” in Sudanese officials who were essential to the peace agreement between Khartoum and opponents in another part of the country, in the south. The idea was that the north-south agreement would also lead to lowering the level of violence in Darfur. The fact that fighting rages on in Darfur, and that the government has indeed increased the air attacks recently, is a mere “inconvenience,” Ms. Lefkow said.

Mr. Coebergh, the British doctor, attributes the oft-cited figure of 70,000 deaths to a September 2004 report by the World Health Organization. The figure was given to journalists by the head of the WHO, Dr. David Nabarro. It stuck, although Mr. Nabarro later explained that the number was partial, according to Mr. Coebergh.

“Our only source of information on mortality rates are the surveys carried out amongst internally displaced people in camps in Darfur and among refugees in eastern Chad,” Mr. Coebergh writes. “Using the surveys, it is possible to establish a likely range of total deaths from violence and disease and malnutrition.” After combining reports by WHO, Doctors Without Borders, the U.N., the State Department, and NGOs active in Darfur, he concluded that “the true death toll is nearer 300,000.”

“Does it matter how many have died?” he writes. “Yes. It gives us a correct picture of the scale of the tragedy in Darfur and helps us measure our response. Counting the dead also values them. And it allows us to properly estimate the cost in lives this war will claim in the months ahead. After all, these were, and are, preventable deaths.”