LOS ANGELES (Reuters) - Three weeks after a mob attacked pro-Palestinian activists encamped at the University of California, Los Angeles, police have made their first arrest in the violence, a man they say was seen in video footage beating victims with a wooden pole.

The suspect, identified as Edan On, 18, was taken into custody on Thursday in the city of Beverly Hills and booked on suspicion of assault with a deadly weapon, the UCLA Police Department said in a statement on Friday.

The man, who police said had no affiliation with UCLA, was reported by local media to be a Beverly Hills High School student.

His arrest was the first by police in their investigation of the violence that flared on campus between pro-Palestinian activists occupying a tent camp to protest Israel's war in Gaza, and a group who attacked them late on the night of April 30.

The masked assailants, described by university officials and police as "instigators," stormed the protest site with clubs and poles, sparking a pitched skirmish in which both sides traded blows and doused each other with pepper spray. The encampment occupants said fireworks were also hurled at them.

University officials and police came under harsh criticism from California Governor Gavin Newsom and others for how they responded to the confrontation, which continued for at least three hours into the early morning of May 1 before police moved in and restored order.

(Reporting by Steve Gorman in Los Angeles and Andrew Hay in Taos, New Mexico; Editing by Chris Reese)

By Steve Gorman and Andrew Hay