U.N. experts are concerned that Sudan is sliding into a "human rights abyss" in the aftermath of the Sudanese security forces' deadly break-up of the main protest sit-in in the capital, Khartoum.

The experts, appointed by the U.N. Human Rights Council, called on Wednesday for an independent investigation into violations against peaceful protesters in Sudan.

A statement from the experts says they're alarmed at reports of numerous deaths since June 3, when security forces violently dispersed the protesters outside the military headquarters in Khartoum.

The protesters were demanding the military speedily hand over power to civilian rule but the generals refused.

Following the bloody break-up, the protesters called off their general strike and civil disobedience campaign.

Since then, shops and businesses have reopened and there's more traffic on Khartoum streets.