A controversial doctor who provided late-term abortions was fatally shot as he walked into his Kansas church, and authorities said they have arrested a suspect in the case.
Abortion doctor George Tiller was murdered just after 10:00 am (1500 GMT) in the lobby of Reformation Lutheran Church in Wichita, Kansas, police and city officials said.
President Barack Obama decried the killing in a statement released by the White House.
"I am shocked and outraged by the murder of Dr George Tiller as he attended church services this morning," said Obama.
"However profound our differences as Americans over difficult issues such as abortion, they cannot be resolved by heinous acts of violence."
Wichita officials said the suspect, who was not identified, was arrested some three hours after the killing. Local media identified the suspect as a 51-year-old man, who would be returned to Wichita to be charged.
"It's an unfortunate incident to happen on a Sunday morning," Wichita police captain Brent Allred told reporters. "These things should not occur at a any time."
Long a lightning rod in the bitter US culture war over abortion, Tiller, 67, over the years had been picketed, bombed and even shot.
His was one of only three clinics in the United States that perform late-term abortions, which are performed on fetuses that would be viable outside the mother's womb.
Late-term abortions are legal in Kansas if two independent physicians agree that the mother could suffer irreparable harm by giving birth.