Colorado Springs - Three people were killed and several wounded when a gunman opened fire at a family planning centre in Colorado in a standoff that dragged on for five hours Friday before he surrendered.
A large area of snow-covered Colorado Springs was placed on lockdown into the evening, just a day after millions of Americans celebrated the Thanksgiving holiday, in the latest incident to shed a damning light on the United States' gun culture.
Mayor John Suthers paid tribute to police for getting the gunman into custody without further bloodshed at the Planned Parenthood building, where people scrambled into a safe room in a desperate bid to save themselves.
A police officer was among the dead, he said, while nine others - among them five police - were wounded. None of the injured were in a serious condition.
"I want to convey to the loved ones of the victims: this is a terrible, terrible tragedy that occurred here in Colorado Springs today," Suthers told reporters.
"Obviously, we lost two civilian victims, we mourn the loss of a very brave police officer." It was not immediately clear if the Planned Parenthood family planning centre had been specifically targeted.
Abortion is one of the services Planned Parenthood provides for women, and the association has become a lightning rod for criticism by social conservatives.
The women's health care giant has also been mired in a months-long scandal after anti-abortion activists released secretly recorded videos showing the organisation's officials discussing use of aborted fetal tissue for medical research.
Earlier, there had been fears that the unidentified gunman might have explosives with him, and police were carefully combing the scene after the siege came to an end when he surrendered.
Speaking at the scene before the standoff ended, police spokeswoman Lieutenant Catherine Buckley warned that the gunman had taken "items" and bags inside the building with him.
An unknown number of people were inside the clinic at the time of the shooting, on what had been a regular working day at Planned Parenthood, a day after Thanksgiving.
A sheriff's department SWAT team with at least one armored vehicle and several ambulances had also been on standby, as the evening drew in on the snowy scene.
The immediate vicinity was placed on lockdown and people were told to stay indoors.
Buckley said the shooter was armed with some kind of "long weapon" with a shoulder stock such as a rifle and some witnesses reported hearing automatic fire.
Quan Hoang, the owner of a nearby nail salon, told CNN that when he heard the gunfire break out, he feared a robbery was under way at a bank in the shopping area, which would have been bustling with people looking to pick up a bargain in the Black Friday sales.
"And we see cops, SWAT, the bomb squad, a whole bunch of people just trying to take cover around the Planned Parenthood area," he said by telephone.
"An officer came back in and said, 'Is everyone safe?' We asked him questions and he said they've barricaded him inside the Planned Parenthood and he was shooting out from the windows." A White House official said that President Barack Obama had been notified of the incident by his Homeland Security Advisor Lisa Monaco.
Vicki Cowart, president and CEO of Planned Parenthood Rocky Mountains, said that her initial information was that none of her staff or patients had been killed or injured.
Cowart said that she did not believe the centre had been specifically targeted.
"We're very pleased that our own security systems were operating at top-notch," she told CNN.
That included rushing into a safe room.
"They were able to hunker down and some got out early throughout the afternoon, but those that didn't were in a safe spot," Cowart said.