The revolt began as a student demonstration, which attracted thousands as they marched through central Budapest to the Parliament building, calling out on the streets using a van with loudspeakers via Radio Free Europe. A student delegation entering the radio building to try to broadcast the students' demands was detained. When the delegation's release was demanded by the demonstrators outside, they were fired upon by the State Security Police (ÁVH) from within the building. As the news spread, disorder and violence erupted throughout the capital.