UNITED NATIONS — U.N. Secretary-General Ban Ki-moon Monday condemned the latest wave of bloodshed in Egypt, calling for an independent inquiry into fresh violence which left more than 50 people dead.

Fifty-one people, mostly loyalists of ousted Egyptian president Mohammed Morsi, were killed outside an army barracks in Cairo on Monday.

Ban's spokesman Martin Nesirky said the U.N. leader was "deeply disturbed" by the killings, which have been described by Morsi's supporters as a "massacre."

"The Secretary-General condemns these killings and calls for them to be thoroughly investigated by independent and competent national bodies, and those responsible need to be brought to justice," Nesirky said.

The Secretary-General "calls on all Egyptians to be mindful of the precarious path the country is now on and to do everything possible to avoid further escalation," Nesirky added.

Ban urged all sides in the violence to exercise "maximum restraint."

"Protests must remain peaceful and the security forces must abide strictly by international standards," Nesirky said.

Ban called on Egyptians and political parties "to work constructively to forge a consensus on the way forward through peaceful means."

"The United Nations stands ready to assist as necessary," Nesirky added.