The dire situation of 2.7 million refugees in Sudan's Darfur region has reached a new crisis after the nation's president expelled 13 agencies that advocates say supplied half the aid that keeps refugees alive.

That is the message that Jerry Fowler, president of the Save Darfur Coalition, brought to Pittsburgh on a three-day visit. He spoke to about 30 religious activists at East Liberty Presbyterian Church yesterday.

Violence erupted in the impoverished region in 2003, after rebels attacked government targets, claiming that the Sudanese government oppressed the black Darfurians and favored an Arab cultural elite. According to the United Nations and humanitarian groups, the government -- or militias allied with it -- responded by indiscriminately torturing, raping and killing civilians, destroying their crops and their wells.

While the worst violence ended after 2005 with an estimated 300,000 dead, Mr. Fowler said, 2.7 million refugees remain dependent on outside aid.

Their perilous status quo was thrown into turmoil last week when the International Criminal Court in the Hague indicted President Omar al-Bashir for war crimes and crimes against humanity. A statement on the Web site of Sudan's embassy called the charges "one of a series of plots against Sudan that aim to prevent the country from becoming a model for freedom." The site confirmed that Sudan had banished 13 aid groups, accusing them of political activity, kidnapping children and other violations.

Mr. Fowler believes the Sudanese government banished major aid groups "because they are desperate. They believe if they raise the ante [of danger to the refugees], there will be a back-off on the indictment," he said.

Still, he believes the indictment presents an opportunity.

"The Sudanese government has been successful to a disturbing degree at portraying themselves as victims of neo-colonialism ... which resonates with other governments in Africa and the Arab world," he said.

But the International Criminal Court is global, with members from 30 African nations, but not from the U.S., Mr. Fowler said. The judges who issued the charges were from Brazil, Ghana and Latvia, which should undermine the rhetoric about colonial persecution, he said.

He called on President Barack Obama to echo Archbishop Desmond Tutu of South Africa, a Nobel Peace Prize winner who has asked how African leaders can support Mr. Bashir when the victims were Africans.

"The moral authority of President Barack Obama in this arena is incredible" because of his African heritage, Mr. Fowler said.

At the White House Monday, Mr. Fowler said he pressed presidential advisers to swiftly organize a diplomatic effort to isolate the Sudanese government. Mr. Bashir cares about his global standing, so losing an invitation to meetings such as the Arab League summit could change his behavior, Mr. Fowler said.

Mr. Fowler wants Mr. Obama to call the heads of key African and Arab states to urge them to isolate and pressure the Sudanese government. He also wants him to appeal to the Chinese, who have vast oil interests in Sudan, arguing that their investment will be safer in a peaceful, stable Sudan.

"He can back up the calls by deploying a full-time envoy whose focus is on Sudan policy ... someone high-level with the stature and authority to represent the president," he said.

Mr. Fowler's organization has collected more than 250,000 post cards -- 11,000 from Pittsburgh -- that will be delivered to Washington next month urging the president to take action in Darfur.

Information on his campaign is at www.savedarfur.org and www.pittsburghdarfur.org. The Sudanese government is at www.sudanembassy.org.