Sudanese men burn tires during a demonstration to commemorate the third anniversary of a deadly crackdown carried out by security forces on protesters in Khartoum, on June 3. AP Photo
Sudanese men burn tires during a demonstration to commemorate the third anniversary of a deadly crackdown carried out by security forces on protesters in Khartoum, on June 3. AP Photo

Sudan's pro-democracy groups reject calls to drop boycott of UN-sponsored talks