The Sudanese President, Omar al-Bashir, has left Nigeria amid calls for his arrest over genocide charges, his embassy has confirmed.
The embassy spokesman Mohammed Moiz told the AFP news agency on Monday night: ""He has left. He left in the afternoon."
Earlier, a Sudanese diplomat, who would not give his name, told the AP news agency that Bashir had left at 3pm local time on Monday, less than 24 hours after he arrived, and in the middle of a two-day summit ending on Tuesday.
Moiz and the diplomat denied that Bashir's sudden departure was because human rights lawyers in Nigeria had filed a lawsuit on Monday to try to compel the government to detain Bashir and surrender him to the International Criminal Court (ICC) for trial on charges of war crimes committed in Sudan's Darfur conflict.
The embassy spokesman said the president had another engagement.
A civil rights group had also urgently appealed to the ICC to refer the government to the UN Security Council for allowing the visit.
Bashir had arrived in Nigeria on Sunday for an African Union summit on HIV and AIDS, angering human rights groups who said he should not have been made welcome.
Nigeria defends welcome
Nigeria's presidency defended welcoming Bashir to the country for the summit in spite of the war crimes charges against him.
The presidential spokesman Reuben Abati told AP that 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 co-operate with the European-based court which some accuse of targeting Africans.
The ICC issued two warrants against Bashir in 2009 and 2010 for war crimes, crimes against humanity and genocide over the conflict in Sudan's Darfur region.
Since Nigeria is a member of the ICC, it technically has a legal obligation to arrest suspects wanted by the court.
Some African Union members and officials have criticised the Bashir indictments, and the body has passed a resolution that called on its members not to co-operate with the warrants.
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.