Sudan's President Omar al-Bashir travelled on Sunday to a health summit in Nigeria, official media said, after Human Rights Watch urged authorities in Abuja to arrest him for war crimes charges.
Bashir "left today for the Nigerian capital Abuja to participate in the African Union summit about HIV, TB and malaria to be held over two days," the state SUNA news agency said.
Nigeria is a member of The Hague-based International Criminal Court, which in 2009 and 2010 issued two warrants against Bashir for war crimes, genocide and crimes against humanity allegedly committed in Sudan's Darfur region.
His visit marks "a real test of Nigeria's commitment to the ICC", Elise Keppler, associate director of the International Justice Programme at Human Rights Watch, told AFP ahead of Bashir's trip.
Some ICC members including Chad, Djibouti and Kenya have allowed visits by Bashir, but others like Botswana, South Africa and Uganda have ensured that he stays away.
A number of states "have found a way out of this problem and Nigeria should do the same," Keppler said, urging Nigeria to arrest him if he sets foot in the country.
Nations that have signed on to the world's only permanent court for war crimes and crimes against humanity have a legal obligation to arrest any indicted suspect found within their territory.