The rider of what the San Francisco Police Department made an effort to specify was a "fixed speed" bicycle is dead after a collision with an SFPD patrol car Friday night.

According to SFPD spokesperson Officer Albie Esparza, at 9 p.m. Friday officers were on patrol, driving westbound on Persia Avenue toward Sunnydale Avenue, near McLaren Park.

"They were just driving regular, no lights or sirens, not going to a call, just regular, routine driving approaching this intersection,” Esparza told KPIX.

"At a bend just prior to Sunnydale, a collision occurred between a marked police vehicle and a bicyclist," Esparza said in a written statement sent to media Friday evening.

"It's unclear if the patrol vehicle collided with the bicyclist or the bicyclist hit the patrol car," he wrote.

ABC7 reports that the cyclist "apparently rode into the roadway from a trail and it was very dark when the crash took place."

Calling for an ambulance on police radio, an officer said “We’ve got a bicyclist down, bleeding profusely from the face,” the Chron reports.

However, the cyclist, a man in his 20s who, as of Saturday morning had not been publicly identified by the San Francisco Medical Examiner's office, "was deceased on scene," Esparza says.

According to Bay City News, the cyclist was not wearing a helmet when the collision occurred.

"The bicycle was a fixed speed," Esparza notes in his statement. More frequently described as a "fixed-gear" bicycle, "fixies" (as they are commonly known) have in recent years gained popularity with cyclists in urban areas.

Esparza did not note any technical specifications of the patrol car from the collision in his statement.

"This is a tragedy, our thoughts go out to the bicyclist's family, as well as out two officers involved as this is a tragic incident," Esparza says, vowing that SFPD's Traffic Collision Investigations Unit and CSI will conduct a thorough investigation.

Esparza says that "an administrative process will also be conducted for the driver," which will include a toxicology report.

Esparza says that the department is also seeking witnesses to the collision, asking anyone who might have seen it to contact SFPD anonymously at 415-575-4444 or to text-a-tip to TIP411 with SFPD at start of message.