Updated

A Mexican man has been charged with assaulting a Border Patrol agent near San Diego in a scuffle that some activists said shows the agent used excessive force.

Vulfrano Merino punched the agent in the chest and repeatedly tried to hit him again, according to the federal complaint filed Wednesday. He allegedly continued to resist after the agent shot him in the back with a stun gun.

Merino was pulled over Monday in a van with three others near Santa Ysabel, about 50 miles northeast of San Diego. The driver captured part of the scuffle on his phone and shared the video with KGTV, which aired portions of it. The Border Patrol went to the man's home hours after the scuffle and seized the video.

Merino was also charged with a felony count of re-entering the country after being deported. He did not enter a plea during his initial court appearance Wednesday and was ordered held without bail. His court-appointed attorney, Victor Pippins, declined to comment Thursday.

The video showed the agent punching Merino in the face and upper body and kneeing him in the ribs, said Pedro Rios, director of the American Friends Service Committee's San Diego office. A bystander who helped the agent appears to have pinned Merino's legs.

"I would qualify that as excessive force," Rios said.

Border Patrol spokesman Pete Vasquez rejected allegations of excessive force and said the agent acted in self-defense.

The scuffle began shortly after two agents ordered Merino and another man who were suspected of being in the country illegally to step out of the van, according to the complaint. The other man allegedly fled, prompting one of the agents to chase him.Man charged with assaulting Border Patrol agent

The driver permitted Border Patrol agents who visited his home to view the video, which was seized as evidence, Vasquez said. The Border Patrol alerted the driver's parole officer to the incident.

KGTV reported that the driver had refused to help agents locate the man who fled and that he was later arrested for a parole violation.