OAKLAND -- A Moraga man was critically injured Tuesday evening when he fell from his bicycle while riding down a street in Montclair.

The 80-year-old man was riding a blue "Titus Racer X" full-suspension bicycle going southbound in the 5600 block of Colton Boulevard about 5:53 p.m. Tuesday when he lost control for unknown reasons and flipped over the handlebars landing in the roadway, witnesses told police.

No other vehicles were apparently involved, police said.

The man's name has not been released, but investigators said he is an enthusiastic bike rider who regularly rides between Moraga and Oakland.

Several people in the area gave first aid to the man before paramedics arrived. He was transported to Highland Hospital, where he was unconscious in critical condition on Wednesday.

Police continue to investigate the accident. Anyone with information about the crash is asked to call police at 510-773-8650.