Tens of thousands of people rallied in cities across the world Sunday to protest the violence in the war-torn Darfur region of Sudan, and urge world leaders to intervene to resolve the conflict.

Tens of thousands of people demonstrated in New York City, religious leaders gathered outside Downing Street in London to pray for a resolution, and a candlelight vigil was held in Cambodia to remember Darfur victims.

In a counter demonstration, about 150 people in Khartoum, Sudan, marched to the United Nations' offices to protest the proposed deployment of U.N. peacekeepers in Darfur.

Protests and other events for the "Global Day for Darfur" were scheduled in four dozens cities worldwide to show support for Darfur's people and pressure the Sudanese government to protect its civilians and end the conflict.

CountryWatch: Sudan

At least 200,000 people have been killed in Darfur and more than 2 million have fled their homes since 2003, when ethnic African tribes revolted against the Arab-led government. The government is accused of unleashing brutal Arab militiamen known as janjaweed in the remote western province.

Sudanese President Omar al-Bashir again rejected U.N. peacekeepers during a meeting with U.N. Secretary-General Kofi Annan on Saturday. Annan had urged Sudan to accept the U.N. Security Council's decision to replace the largely ineffective African Union peacekeeping force with better-equipped U.N. troops.

On Sunday, New York police estimated that 20,000 attended the demonstrations. Organizers said more than 30,000 attended.

U.S. Rep Chris Smith, R-N.J., said the people of Darfur have "had atrocities imposed upon them that no human being would have to face." Smith added that China, which has major oil interests in Sudan, should "put its economic interests in Sudan aside and say enough is enough."

In London, Christian, Muslim and Jewish leaders evoked the 1994 genocide in Rwanda, where more than 500,000 people were slaughtered. The leaders were met by Baroness Amos, leader of the House of Lords, who warned that the world must not once again turn a blind eye to an unfolding crisis in Africa.

"We do not want to see a repeat of what happened in Rwanda when the world community turned its face away," she said.

The gathering followed a march from the Sudanese Embassy by hundreds of protesters wearing the light blue berets of the U.N. to represent their call for a U.N. force in the area.

Amos said the UK government would call for sanctions and the investigation of human rights abuses by the International Criminal Court.

In Phnom Penh, Cambodia, still haunted by memories of the brutal Khmer Rouge regime's rule in which some 1.7 million were killed in the late 1970s, protesters held a candlelight vigil in a local mosque.

Ly Sok Kheang said he feared the international community was repeating the same mistakes from Cambodia.

He said, "As far as the genocide in Cambodia is concerned, for over three years the state committed killings of its own people while the international community, including the United Nations, failed to intervene to stop it."