Sudanese leader Omar Al-Bashir has left Nigeria, a diplomat at his embassy said Tuesday, following demands from human rights activists for the arrest of the man indicted for genocide and war crimes in Darfur.

Human rights lawyers filed a suit in the Federal High Court on Monday to try to compel Nigeria's government to arrest Al-Bashir. And a civil rights group urgently appealed to the International Criminal Court to refer the government to the UN Security Council for allowing the visit.

Presidential spokesman Reuben Abati told The Associated Press that al-Bashir had come to attend the African Union summit, and not at Nigeria's invitation. He said Nigeria's action in allowing him to come was in line with instructions from the African Union, which has told its 53 member states not to cooperate with the European-based court that some accuse of targeting Africans

Nigeria was forced in the past to hand over an internationally wanted criminal — former Liberian President Charles Taylor, the warlord who began that country's devastating civil war in 1989.

In 2003, Taylor resigned under pressure and a promise from Nigeria's government to give him a safe haven. When democratically elected leader Ellen Johnson Sirleaf demanded his extradition in 2006, Nigeria came under huge international pressure and was forced to go back on its word and hand him over.

Taylor was sentenced to 50 years in prison by the International Criminal Court in May, not for crimes committed in his own country but for his responsibility for war crimes and crimes against humanity committed in neighboring Sierra Leone.

A diplomat at the Sudanese embassy in Abuja, the Nigerian capital, told The Associated Press that al-Bashir left at 3 p.m. Monday, less than 24 hours after he arrived and in the middle of a two-day summit ending Tuesday. The diplomat, who refused to give his name, said his hasty departure had nothing to do with the pressure for his arrest.

Leaders from eight other African countries are attending the summit, including Kenya, which has shunned al-Bashir.

South Africa, Malawi, Uganda, Kenya, Zambia, and Central Africa Republic "have specifically made clear Bashir will be arrested on their territory, seen to it that other Sudanese officials visit instead of Bashir, relocated conferences or otherwise avoided his visits," said human rights lawyer Chino Obiagwu, who heads the Nigerian Coalition on the ICC.