Sudanese authorities have detained around 50 delegates from local and international human rights groups as they met on the sidelines of an African Union summit in Khartoum. Rights activists, being detained in a building where the meeting was being held, said Sunday's crackdown called into question Sudan's right to host the AU summit. Osman Hummaida, from the Sudanese Organisation Against Torture (SOAT), said: "Towards the end of the meeting a group of security men came and demanded to see the agenda, the list of participants and our recommendations."Everyone is being detained and we have been asked not to talk on the phone. We have not been told why we are being held," he said. The meeting was to discuss closer co-operation with the AU on human rights issues. Representatives of Amnesty International, Anti-Slavery International and the International Bar Association were among those being held, Hummaida said. Mudawi Ibrahim Adam, a Sudanese human rights activist who has previously been arrested by the government, said: "They are harassing people and trying to get all the laptops from them. They cannot be hosting a summit while they have this kind of conflict and they cannot be the chairperson of the African Union."