By Daniel Woolls
US President Barack Obama has denounced the country's epidemic of gun violence and renewed a call for tougher controls on military-style weapons after yet another deadly shooting, saying "enough is enough."
The latest bloodshed came on Friday (local time) when a man entered a family planning clinic in the state of Colorado and allegedly opened fire, killing three people, including a police officer, and wounding nine others.
The motive of the suspect now under arrest was not yet known and police were to interrogate him on Saturday.
The Planned Parenthood clinic located in Colorado Springs performs abortion, and the city's mayor suggested that deeply divisive issue in America may have been behind the assault.
"You can certainly infer what it may have been in terms of where it took place and the manner in which it took place," John Suthers told CNN.
The tragedy came a day after Americans celebrated their cherished Thanksgiving holiday, a time to relax with family, and which ushers in the holiday season in earnest.
Obama said the suspect had been armed with an assault weapon - the first official word of this detail - and he also disclosed for the first time that the man had held hostages at the Planned Parenthood centre from which he opened fire at people outside in an hours-long stand-off with police.
"We have to do something about the easy accessibility of weapons of war on our streets to people who have no business wielding them. Period. Enough is enough," Obama said in a statement.
The gunman had entered the Planned Parenthood clinic around noon on Friday and started shooting from a window. Police surrounded the building, and after an exchange of gunfire and a stand-off lasting more than five hours the gunman surrendered.
Local police on Saturday identified the suspect as 57-year-old Robert Lewis Dear. News reports said he was from South Carolina.
It was unclear whether Planned Parenthood - a major women's health and family planning group - was the shooter's target.
Abortion is one of many services Planned Parenthood provides for women, and the association has become a lightning rod for criticism by US conservatives, among other reasons because it receives funding from the government for some health services.