At least two photographers with other media faced beatings and brief arrests.
Robayo said the troops beat him as they sought to stop him from taking pictures of clashes between demonstrators and the National Guard on Caracas' Francisco Fajardo highway.
"The National Guard started to go by on motorbikes. They approached and one of them hit me several times in the head, then they pushed me and I fell. They lifted me up by the (bulletproof) vest, and my camera fell," he recalled.
One of them tried to take off Robayo's gas mask and arrest him only to be told to stop by a superior, the photographer said.
Guards took away the photographer's vehicle and belongings, his driver said.
At least two photographers with other media faced beatings and brief arrests, professional associations and colleagues said.
Opposition activists and government supporters were staging the latest in two months of street protests, with fresh clashes between prosecutors and police.
Prosecutors say the unrest has left 60 people dead so far.