The man accused of opening fire at a Planned Parenthood clinic in Colorado and killing three people said "no more baby parts" while he was being arrested, NBC News and other media reported, citing unidentified law enforcement sources.

The utterance from suspect Robert Lewis Dear, 57, apparently referenced the organisation's health services, which include abortion, and its role in delivering foetal tissue to researchers.

It could hint at a possible motive for the rampage on Friday, though NBC, citing sources, said investigators had not confirmed any motivation.

Authorities have not discussed a motive for the attack at the Colorado Springs clinic, which killed a police officer and two civilians and wounded nine.

"This unconscionable attack was not only a crime against the Colorado Springs community, but a crime against women receiving healthcare services at Planned Parenthood, law enforcement seeking to protect and serve, and other innocent people," Attorney General Loretta Lynch said in a statement.

The wounded included five police officers and four civilians, who were listed in good condition at area hospitals.

Garrett Swasey, 44, who was killed, was a campus police officer for the University of Colorado at Colorado Springs who joined city police responding to the shooting. The father of two served as an elder at Hope Chapel, the church said on its website.

Dear, a South Carolina native who appeared to have moved to Colorado last year, was taken into custody at the clinic after an hours-long stand-off with police and jailed ahead of a Monday court appearance.

In a statement, Vicki Cowart, chief executive of Planned Parenthood of the Rocky Mountains, said: "This is an appalling act of violence targeting access to health care and terrorising skilled and dedicated health care professionals."

The shooting was believed to be the first deadly attack at an abortion provider in the United States in six years.

The Colorado Springs centre has been repeatedly targeted for protests by anti-abortion activists.

Planned Parenthood was criticised this year after officials of the organisation were secretly recorded by an anti-abortion group discussing how to obtain human tissue from aborted foetuses.

The videos triggered protests and have become an issue in the 2016 presidential election race, as conservatives in Congress seek to cut off Planned Parenthood's federal funding.

Planned Parenthood has strongly denied doing anything illegal or unethical.

At least eight workers at clinics providing abortions have been killed since 1977, according to the National Abortion Federation.