Story highlights Sudanese President Omar al-Bashir is in Johannesburg, South Africa, for African Union summit

Lawyers' group demands his arrest; judge rules to keep him in country while legal battle plays out

African Union tells member states not to cooperate with international court because of Africa bias

(CNN) The International Criminal Court's six-year quest to arrest Sudanese President Omar al-Bashir on charges of war crimes and genocide took a step closer to reality Sunday after he arrived at the African Union summit in South Africa.

The North Gauteng High Court in Pretoria barred al-Bashir from leaving the country while hearings determine the fate of the ICC arrest warrant, a spokesman for the legal team seeking his detention told CNN.

The state asked Judge Hans Fabricius to delay proceedings until Sunday afternoon to give it time to prepare its arguments, and the judge agreed, Kaajal Ramjathan-Keogh of the Southern Africa Litigation Centre said from the high court.

Lawyers for the litigation center asked for a court order that would prevent al-Bashir from leaving South Africa until the court delivered its decision, and Fabricius granted that motion as well, Ramjathan-Keogh said.

Fabricius wants to determine whether it's legally acceptable for Pretoria to allow al-Bashir to visit South Africa without arresting him, and key in that decision will be determining if the South African Cabinet's decision not to comply with the ICC demand can trump an international treaty, South Africa's Mail & Guardian newspaper reported