An assault on a Metrobus driver -- part of a violent trend that has drivers calling for additional security -- was captured on videotape by an onboard camera, Metro officials said.

The June 1 attack near the Rhode Island Avenue Metro station marks the first time an assault on a driver was recorded by a camera, and Metro Transit Police are asking the public to help identify the rock-hurling man.

The driver, whose identity is being withheld by Metro, was behind the wheel of a bus on the P6 line when it came to a stop at Third and T streets NE at 2:19 p.m., said Linda Foxwell, a transit police officer. A passenger got off the bus and a man, who had been standing on the street, climbed up the first step of the bus and threw a "baseball-sized" rock into the face of the driver a few feet away, Foxwell said.

The man got off the bus, the driver closed the doors and the man picked up another rock, which he tossed at the bus as it sped away, Metro spokeswoman Lisa Farbstein said.

The driver, who has worked for Metro for six years, was bleeding from his lip and chin but finished his route and called for help when he reached the end of the line, the Rhode Island Avenue Station. He was taken to a hospital where he received stitches for the cuts on his face and was released, Farbstein said.

About 25 passengers were on the bus at the time of the assault, Farbstein said. The bus was one of 100 in the 1,460-bus fleet that is outfitted with security cameras. One camera was pointed at the front door and recorded the suspect throwing the rock, Foxwell said. "We're asking the public's assistance in identifying him," she said.

The number of assaults on buses rose to 125 last year from 114 in 2003. There were 66 assaults on bus drivers last year compared with 46 in 2003, according to transit police statistics.

In February, Metro's largest union, Local 689 of the Amalgamated Transit Union, protested outside Metro headquarters and demanded better security for bus drivers. The board of directors approved a plan to outfit an additional 250 buses with cameras but that equipment will not be installed until fall, Farbstein said.

The P6 line travels between the Anacostia Metro station in Southeast Washington and the Rhode Island Avenue Station in Northeast, with stops on Capitol Hill, along the Mall and in Chinatown.

The assault took place as the bus was traveling through the Edgewood neighborhood near the end of the route in Northeast. Foxwell could not provide crime statistics for the line. "It would take a long, exhaustive search," she said.

An onboard camera catches a man throwing a large rock at a Metrobus operator at Third and T streets NE. The bus was one of 100 in the Metrobus system outfitted with cameras.Transit police are asking the public to help identify the rock-hurling suspect who boarded a P6 bus.After the suspect got off the bus, he threw another rock at the bus as it drove away, police said.