At least six people were injured within in an hour or two Tuesday afternoon in four separate traffic crashes in the District, officials said.

One of the accidents involved a bicycle, another involved a Metro Transit Police car, and in still another, someone was struck while in a wheelchair, according to law enforcement and fire and rescue spokesmen.

All three accidents happened on busy city streets during the afternoon rush hour on a sweltering summer afternoon. None of the injuries appeared to be life-threatening.

In the first incident, a woman on a bicycle was seriously injured about 4:30 p.m. in a collision on Georgia Avenue that involved three cars. The woman was taken to a hospital after the incident near Otis Street NW.

Shortly after 5 p.m., a Metro transit police car was among three vehicles in a collision at 7th and G Streets SW, near the Southwest Waterfront. The police vehicle was headed south on 7th with its emergency lights flashing when it collided with a Jeep that was heading east, said Metro spokesman Dan Stessel. The Jeep then struck a third vehicle, authorities said.

Two police officers, the Jeep driver and a fourth person were injured.

Also around 5 p.m., a pedestrian was struck by a vehicle at 11th and W Streets NW, said D.C. police spokesman Paul Metcalf. The site is near the busy U Street corridor. Authorities said the man was conscious and breathing when found.

That incident occurred at around the same time and place where a man in a wheelchair was reported hit by a car, according to preliminary accounts, said D.C. Fire and EMS spokesman Pete Piringer.