Kofi Anann (l) and Sudan's State Minister of Foreign Affairs Najeeb Khair
U.N. Secretary-General Kofi Annan has visited Sudan's South Darfur state to take a first-hand look at the security situation in the troubled region.

Mr. Annan listened Saturday as refugees complained about attacks by police and Arab militias on the Kalma camp, which is home to some 100,000 people displaced by two years of war. A refugee leader said 56 people have been killed in the camp since their arrival.

Aid workers told the U.N. chief that while security in and around the camp remains a problem, it has improved with the arrival of African Union troops.

Mr. Annan called on Sudanese leaders to do more to improve the situation in the camps.

International donors recently pledged an additional $300 million to expand the AU peacekeeping mission.

Some information for this report provided by AFP and AP.