The deaths of three dozen Islamist detainees in Egyptian police custody  this week prompted U.N. chief Ban Ki-moon  on Monday to call for a “full investigation” into the incident.
Ban said he was "deeply disturbed by the reported deaths” of the prisoners as they were being transferred to a different facility in Cair o, according to his spokesman Martin Nesirky.
“He calls for a full investigation to ascertain the facts surrounding this incident,” Nesirky said, as quoted by AFP news agency.
The Egyptian government said 37 Islamist detainees died on Sunday after police fired tear gas in a bid to free an officer taken hostage by prisoners, as the inmates were being transferred to a north Cairo jail.
But Egypt’s Anti-Coup Alliance , supporters of deposed Islamist President Mohammad Morsi, said it had "obtained evidence of the assassination of anti-coup detainees in a truck transferring them to Abu Zaabal prison.
"They were reportedly assassinated in their truck with live ammunition and tear gas fired from windows."
The Muslim Brotherhood held the police accountable, accusing them of “murder,” AFP reported.Ban also condemned a militant ambush of police buses in Egypt’s Sinai Peninsula on Monday that left 25 policemen dead .