Bashir traveled Monday to Chad for a regional conference of Sub-Saharan and Sahel states in Africa. He's wanted by the International Criminal Court for genocide, war crime and crimes against humanity in the troubled Darfur region of Sudan.
International Justice Counsel for Human Rights Elise Keppler said there was a growing chorus of African voices calling for Bashir's arrest.
Bashir was last in Chad in February for a meeting of Sahel and Saharan African leaders. Tiina Intelmann, the president of the assembly of state parties to the Rome Statute of the ICC, said then it was regrettable he wasn't apprehended despite two outstanding arrest warrants.
Chad is a party to the statute that created the ICC. The Chadian government said it was abiding by interests expressed in favor of Bashir by the African Union.
"Chad's international treaty obligations cannot be wiped away by an AU decision," Keppler said in a statement from New York. "Chad should arrest Bashir, not welcome him."