Sudanese opposition leader Sadek al-Mahdi on Friday called for an international investigation into the deadly of a sit-in of demonstrators in Khartoum in early June, after the ruling military refused such an investigation.

The US Assistant Secretary of State for Africa, Tibor Nagy, also called for investigation.

“The United States is convinced of the need for an independent and credible investigation” to establish the responsibilities for these “monstrous events,” Nagy said from Ethiopian capital Addis Ababa after a two-day visit to Khartoum.

The Military Council leading the country since the dismissal of President Omar al-Bashir on 11 April, acknowledged on Thursday that it had ordered the violent dispersion of a sit-in of thousands of demonstrators outside army headquarters in the Sudanese capital on 3 June.

According to a committee of doctors close to the protest, some 120 people have been killed in the crackdown since June 3, most of them in the dispersal of the sit-in. The authorities reported 61 deaths.

The repression took place after the suspension of negotiations between military leaders and protest leaders. The Military Council expressed regret that “errors have occurred”.

“An independent international inquiry should be launched” into the dispersal of the sit-in, Sadek al-Mahdi told AFP after conducting Friday prayers in a mosque in Omdurman, a nearby city in Khartoum.