(CNN) -- The Fresno Police Department has launched an internal investigation after amateur video surfaced of two officers punching and beating a man during his arrest.
The officers involved in the incident were placed on limited duty pending the outcome of an internal probe.
The incident, captured on video by an amateur photographer and aired by CNN affiliate KSEE, occurred on Monday, said police spokesman Jeff Cardinale.
Authorities in Fresno, California, became aware of the recording Tuesday and launched the internal investigation after seeing the video, he said.
KSEE identified the man attacked in the video as 52-year-old Glen Beaty and reported he is homeless. Police Chief Jerry Dyer told KSEE that Beaty had previous violent confrontations with authorities, and that his record includes resisting arrest and injuring a sheriff's deputy.
However, "I think the initial reaction of people that view this video will be one of disbelief," the chief said, according to KSEE. "It will be one that in some cases may shock individuals, one that causes concern in terms of the level of force being used." Watch the tape of the violent arrest »
The video shows officers punching Beaty several times as he lay on the ground.
Beaty was ultimately arrested on a felony warrant Monday, the chief said.
Cardinale said the officers involved in the arrest have been placed on limited duty pending the outcome of the internal investigation. The officers were not identified.
KSEE said it received the video from an amateur photographer, whom it did not identify, but quoted as saying, "I don't think anybody should be beat like that. They don't beat dogs and let you get away with it."
Dyer told KSEE that Beaty was found with alcohol around him and it was apparent he had been drinking heavily. He refused to answer officers' questions and a physical altercation occurred, according to police reports.
"One of the officers was punched by the suspect in the arm," Dyer said. "The officer had his badge ripped off of his shirt. There was also an attempt to jab the officer in the arm with a pen that the suspect had taken from the officer's shirt."
Officers did not use a Taser on Beaty, he said, because he was wearing a heavy jacket at the time.
An ambulance was called to take Beaty to the hospital after the incident, KSEE said, but police did not collect witness statements. Dyer said that would be done as part of the internal investigation. Authorities will allow time for all the evidence to be gathered before making an official opinion, he said.
Beaty was in police custody as of Wednesday, Cardinale said. CNN's attempts to contact him were unsuccessful.