Two cyclists killed in an alleged hit-and-run incident were a married couple from Bristol.
Ross Simons, 32, and his 30-year-old wife Clare died in the crash in Hanham.
A 38-year-old man has been arrested on suspicion of causing death by dangerous driving along with a 35-year-old woman.
The matter has been referred to the Independent Police Complaints Commission, as the police were in pursuit of a car before the fatal collision.
Avon and Somerset Police said that shortly before 4pm on Sunday, an officer's attention was drawn to a Citroen Picasso travelling along Lower Hanham Road at speed.
The officer indicated to the car to stop but it made off.
"The officer began to follow the car but it was lost to sight almost immediately," a force spokeswoman said.
"Very shortly afterwards the car struck another vehicle and then collided with two cyclists on a tandem bicycle."
Mr and Mrs Simons both died at the scene as a result of their injuries.
Inspector Frazer Davey, from the Collision Investigation Team, said: "Following investigations overnight, the circumstances of this collision have become much clearer.
"However, I would appeal to anyone who witnessed this incident or saw this car in the area shortly before the collision to come forward and contact us.
"This is a tragic incident in which two people have needlessly lost their lives. Our thoughts and deepest sympathies are with their families."
The man held in custody handed himself in to police hours after the crash, having fled the scene.
Locals living in the predominately residential street spoke of their shock that a hit-and-run could happen in the area.
Andrea Swerley, 28, lives next to where the police cordon was set up.
The beauty therapist said: "We've not seen anything like this before.
"We got home and saw a helicopter in the air overhead and, looking up the road, which they were just closing, we could see lots of police.
"It's just a shock, nothing like this has happened here before."
Landlord of the Queens Head, Patrick Murphy, said: "It's just not nice that this has happened around here."