As Associated Press photographer has been punched and kicked at a presidential campaign event in Brazil, though he did not suffer serious injuries.

The men who attacked photographer Andre Penner were in plain clothes and didn't identify themselves, though they appeared to be working as crowd control. The incident occurred Friday at a campaign event in Sao Paulo state for presidential candidate Aecio Neves and Sao Paulo Gov. Geraldo Alckmin.

Penner was amid a scrum of photographers caught between onlookers pushing forward toward the candidates and men trying to keep them back. One man punched him and three others joined in the attack.

Neves' spokesman Otavio Cabral says he laments the violence but says nobody from the Neves or Alckmin campaigns was involved. Police are investigating.