Phra Praj Prichano, who resides at Wat Rangsi Chatchawan in Somdej district of Kalasin, filed a complaint to Nonthaburi police station. He said he was attacked by members or supporters of the Radio Broadcasters for Democracy, a faction of the red shirts, after visiting his dying son at Pak Kret Home for Children with Disabilities in Pak Kret district.
The attack took place as he took a taxi from Pak Kret to nearby Soi Anchalee.
The monk said when the taxi was obstructed by the group, he got out and scolded the red-shirt supporters, leading to violence..
Footage of the incident by bystanders showed a crowd angrily yelling at the monk, with some members throwing punches and kicks. One person in the crowd apparently struck the monk with a stick. Voices were heard on the recording telling the attackers to stop, but the attacks continued.
A man snatched away the monk's hammock as he was on the floor, and searched it in front of the hostile crowd. At that point, several individuals intervened and asked the victim to leave the area.
Prior to the attack, about 50 members of a group led by Sornrak Malaithong marched from the Sanam Bin Nam intersection to the NACC main office to criticise the agency's slow progress on the corruption investigation of 396 police stations.
A tent set up by the Nonthaburi People's Democratic Reform Committee (PDRC) to show support to the NACC was present in front of the compound at the time of the movement. Around 20 PDRC guards led by Rachen Trakulwieng and Sukhum Wongprasit were inside.
Outnumbered, they fled the NACC area after the red shirt group broke through a line of about 150 police officers trying to block their advance.
After occupying the area, Mr Sornrak announced that his group intended to stay at the NACC until next Monday, the date of the hearing for caretaker Prime Minister Yingluck Shinawatra, who has been charged with malfeasance over apparently corruption in the rice-purchase scheme.