Nigeria: Sudan's President Omar Al Bashir has left Nigeria amid calls for his arrest on charges of genocide in Darfur.
A human rights group on Monday filed a case in a Nigerian court to try to compel the government to arrest Mr Bashir and hand him over to the International Criminal Court (ICC).
Mr Bashir was in Nigeria for an African Union-organised health summit due to end on Tuesday.
Sudan's embassy in Nigeria said he left because he had another engagement.
The ICC issued an arrest warrant for Mr Bashir in 2009, accusing him of committing genocide during the 10-year conflict in Sudan's Darfur region.
'Breach of obligations'
Sudan does not recognise the ICC and accuses it of being a tool of Western powers, while the AU has called on its members not to arrest Mr Bashir.
Mr Bashir was to due to speak at the summit in the capital, Abuja, on Monday, Nigeria's Guardian newspaper reports.
But when he was called to make a presentation, he was nowhere to be found, it says.
Mr Bashir received a full guard of honour from the Nigerian government when he arrived in Abuja on Sunday to attend the summit, which is looking at ways to curb malaria, Aids and tuberculosis in Africa.
Leaders from eight other African countries are attending the summit, Associated Press news agency reports.
Nigerian presidential spokesman Reuben Abati told AP that Mr Bashir had been in Abuja at the AU's invitation, not Nigeria's.
Nigeria allowed him into the country in accordance with an AU decision not to cooperate with the ICC, he said.
Nigeria was in breach of its international obligations by failing to arrest him, and was fuelling a culture of impunity, NCICC chair Chino Obiagwu said.
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Although Nigeria's government has resisted the calls to arrest Mr Bashir, in 2003, it handed ex-Liberian President Charles Taylor to a UN-backed court to stand trial on war crimes charges, following intense diplomatic pressure from the US.
Mr Taylor had been exiled in Nigeria, and was arrested as he tried to flee.
Mr Bashir has visited numerous African countries since the arrest warrant was issued - including Ethiopia, Kenya and Malawi.