A United Nations team has arrived in Sudan to study if genocide has occurred in the western Darfur region, where fighting has displaced more than 1.5 million people.

The five-member panel was scheduled to meet with top Sudanese officials Monday in Khartoum, before traveling to Darfur later this week.

Last month, U.N. Secretary-General Kofi Annan appointed the panel to investigate alleged human rights violations by pro-government Arab militias sent to quell black rebel groups.  He also asked the panel to identify those responsible for any acts of genocide.

The U.N. Security Council has threatened sanctions against Sudan's government unless it improves humanitarian conditions.

The United States has criticized Khartoum for supporting the Arab militias accused of atrocities against civilians in Darfur.

Some information for this report provided by Reuters.