CAIRO — Egyptian liberal politician Mohamed ElBaradei said the country was in "dire need" of reconciliation and condemned all violence on Monday after at least 42 people were killed in a Cairo protest that turned violent.

"Violence is not the approach no matter what its source, and it must be strongly condemned. I call for an immediate independent and transparent investigation. Egypt is in dire need of reconciliation," he wrote on Twitter.

The Muslim Brotherhood said its supporters were fired on outside the headquarters of the Republican Guard in Cairo.

The military says the Islamists attacked the building, where deposed President Mohammed Morsi was being held.