President Bush ordered sanctions Thursday on four men accused of atrocities in Sudan's Darfur region where three years of conflict have left 180,000 dead.

Bush's order immediately blocks all property and interests in property of the four targeted individuals. It also blocks anyone in the United States from dealing with them.

The president's executive order implemented sanctions imposed Tuesday by the U.N. Security Council on the four men.

They are Gaffar Mahammed Elhassan, former commander of the Sudanese air force's western region; Sheikh Musa Hilal, a Janjaweed chief of the Jalul tribe in North Darfur; and two rebel commanders — Adam Yacub Shant of the Sudan Liberation Army and Gabril Abdul Kareem Badri of the National Movement for Reform and Development.

It was the first time the Security Council had imposed sanctions since the adoption of a resolution in March 2005 authorizing an asset freeze and travel ban on individuals who defy peace efforts, violate international human rights law, or are responsible for military overflights in Darfur.