TRIPOLI - An African mini-summit on Darfur and rising tensions between Sudan and Chad due to take place in Tripoli on Wednesday has been postponed, a Libyan official said Monday. He said the delay followed calls from three of the countries due to take part -- Chad, Egypt and Eritrea -- without elaborating.However, a diplomat in the Libyan capital said earlier that the meeting was called off because of the crisis between Sudan’s government and Ndjamena which has accused Khartoum of supporting Chadian rebels.