The incident took place during a protest in front of the Khmer-Soviet Friendship Hospital on the morning of October 28, 2010, where a group of fifty protesters gathered to seek intervention by the UN Secretary-General into the ongoing Boeung Kak land grab in Phnom Penh. ;Around 10:15AM, as the UN Secretary-General was visiting the Hospital with government officials, a mixed group of armed anti-riot police and administrative police officers launched a violent assault on standing protesters, pushing people to the ground, beating some with walkie-talkies and shocking others with electric batons.

During the incident, Suong Sophorn, an activist who lives in the Boeung Kak Lake area, was arrested and viciously beaten, resulting in a severe bleeding wound to the head. The police dragged him away as he felt unconscious and was further beaten by officers. Sophorn is one among the Cambodians who were protesting the forced eviction of the Boeung Kak Lake community, and was appealing for a meeting with the Secretary-General.