Two Venezuelan opposition leaders were among more than a dozen people wounded by security forces dispersing protests in the capital Caracas against President Nicolas Maduro.
Maduro's adversaries have for two months been blocking highways and setting up barricades in protests demanding he call early elections and address an increasingly severe economic crisis that has left millions struggling to get enough to eat.
Fifty-nine people have died in the often violent street melees, which Maduro calls an effort to overthrow his government.
"We were ambushed," said two-time presidential candidate Henrique Capriles, who accompanied protesters on Monday in an effort to march to the headquarters of the government ombudsman's office, but was blocked by security forces.
"This government is capable of killing or burning anything," Capriles said in a press conference.
He said 16 others were injured in the march, adding he would file a complaint about the issue with state prosecutors.
Legislator Jose Olivares, who is a doctor, tweeted a picture of a bruise on Capriles' face that he said was the result of a soldier hitting him with a helmet during the clashes.
During the same march, opposition deputy Carlos Paparoni was knocked to the ground by a water cannon sprayed from a truck, requiring he receive stitches in his head, Olivares said.
The Information Ministry did not immediately respond to a request for comment.
Source: Reuters news agency