United Nations ? The U.N. Security Council passed a resolution Saturday establishing an international inquiry to determine whether systematic attacks on black African villagers in Sudan constitute genocide.

The measure also calls for increasing the number of African Union troops in Sudan to monitor the government’s efforts to halt militia violence, and it threatens to consider oil sanctions if Khartoum, the Sudanese capital, does not cooperate.

The resolution, which passed with 11 votes in favor and four abstentions, is the council’s second attempt to increase pressure on Sudan to rein in pro-government militias known as “janjaweed.” On July 30, the council passed a first resolution warning Sudan to take action, but since then, Khartoum has made only half-hearted efforts to quell the violence and disarm the pro-government fighters.

While acknowledging improvements in access for aid workers and a decrease in government army attacks on its own population, Saturday’s resolution demanded that Khartoum do much more, much faster.

The United Nations estimates that 50,000 people have died and 1.2 million have been displaced as Sudanese troops and janjaweed have attacked village after village in the western region of Darfur since a rebellion erupted there in 2003.

Although Khartoum denies backing the janjaweed, its obstruction of aid workers caused the situation to cascade into what the United Nations has called “the world’s worst humanitarian crisis.”

U.S. Ambassador John C. Danforth told the council that the disaster in Darfur is uniquely grave because it is entirely man-made.

“It was fabricated by a government as an over-reaction to a rebellion; a government intent on revenge, intent on persecution, intent on breaking the spirit of an entire people,” he said, cataloging government helicopter attacks, rapes and killings that have occurred since the July 30 resolution.

U.S. Secretary of State Colin L. Powell declared last week that the situation in Sudan was indeed genocide after a State Department team interviewed more than 1,100 refugees in Chad. The team heard repeated testimony about intentional acts by largely Arab militias to wipe black African farmers off their land.

Approval of Saturday’s resolution came after a week of intensive negotiations and prodding by Secretary-General Kofi Annan, who said it would be “inconceivable” for the council not to respond to such a dire situation.

Annan told diplomats Saturday that within 10 days he would select an independent international commission to investigate whether the militias’ actions and the government’s obstruction of aid constituted genocide.