A sudden, random attack on three bicyclists last Friday on Nicollet Mall kicked off a melee that had Minneapolis police pursuing 15 to 20 youths who assaulted the bikers and ran through an outdoor restaurant patio as they fled, according to court documents.

The event unfolded in front of police officers patrolling the pedestrian and transit thoroughfare after "numerous, recent 'flash mobs' of individuals engaging in criminal conduct," according to a criminal complaint.

Since early February, attacks on or near Nicollet Mall have involved groups of young men targeting other young men. The attacks put one victim in intensive care, and left another man with a broken jaw.

"It's a big concern for us," said Minneapolis Police Inspector Kris Arneson, who oversees downtown enforcement. The department has stepped up its patrols, made arrests for curfew and truancy violations and is working with schools and the county attorney's office on chronic offenders, she said. In two extreme cases, the police have stripped the rights of two juveniles to come downtown, placing them under "geographic trespassing" restrictions that mean immediate arrest if they're seen in the area.

As for the recent string of attacks, Arneson said social media often play a part in bringing the youths downtown. Once there, a member of the group will pick a target and jump someone. Everyone else then joins in the attack, she said. "They call it 'click mobbing,'" she said. "It's the mentality that they all know they are going to do it."

One of the cyclists who was attacked Friday evening said he and two friends had just pulled up to the intersection of 5th Street and Nicollet Mall when they were jumped.

"We were just biking, the three of us, having some laughs and enjoying the night," said the cyclist, who didn't want his name used out of fear for his safety. It was 7:45 p.m. and the street was crowded with people enjoying the unusually warm evening, he said.

Suddenly "some kid" ran up to the man's friend and punched him in the face, breaking his jaw. Another eight to 10 youths surrounded the cyclists, yelling and trying to provoke a fight.

Two police officers had been watching seven youths at a bus stop when they saw them "suddenly surge" toward the cyclists.

As the officers gave chase, the group fled with one victim's bike. They ran through the seating area at Oceanaire's patio, picking objects off the tables to throw at one of the bicyclists running after them.

Officers caught Antonio D. Jones, 20, of Brooklyn Park. He was charged Monday with felony fifth-degree drug possession, third-degree riot and fifth-degree assault. Officers also arrested three juveniles.

Matt McKinney • 612-217-1747