Three people have died after a man exchanged gunfire with police from inside a birth control clinic in the US city of Colorado Springs, police say.

One police officer and two civilians were killed, Mayor John Suthers said. Several other people were injured.

A male suspect was taken into custody after a stand-off with police lasting hours at the Planned Parenthood clinic.

A number of people were trapped inside the clinic while the stand-off with police took place.

Authorities say the motive for the incident is unclear.

Officials said earlier that 11 people, five of them police officers, had been wounded but it is not clear if the fatalities came from that number.

All roads around the area were closed, the city's police said in a tweet.

The manager of a nearby hair salon, Denise Speller, said she had heard as many as 20 gunshots in under five minutes.

She told a local newspaper she had seen one of two police officers appear to fall to the ground and the other attempt to get the wounded officer behind their police vehicle.

Police had told shoppers at a nearby centre to stay indoors.

In a statement, Planned Parenthood said it was not yet clear "if Planned Parenthood was in fact the target of this attack".

"Our concern is for the safety of our patients, staff and law enforcement," said its CEO Vicki Cowart.

New York's city police said it had deployed critical response vehicles to Planned Parenthood sites in the city because of the Colorado incident, but said there was no threat in the city.

Planned Parenthood is a healthcare non-profit-making group with 59 affiliates and 700 clinics around the US, some of which provide abortion services.

The group has faced numerous protests from those opposed to abortion.