Two officers shot amid protests in Ferguson, the Missouri city that has become a symbol of tensions between police and black Americans, have been released from hospital.
The officers were shot early today in front of the Ferguson police department during a protest following the resignation of the city's police chief in the wake of damning US Justice Department report.
Tensions have been high in Ferguson since August and escalated in November after a grand jury declined to prosecute officer Darren Wilson over the shooting to death of Michael Brown, an unarmed black 18-year-old.
Justice Department investigators agreed with the grand jury's finding in a report released on March 4.
But a separate Justice Department report released that same day found racial profiling and bias in the Ferguson police force, and a municipal court system driven by profit, largely on the backs of black and low-income residents.
The shootings marked the first time in eight months of tension in Ferguson that officers were shot at a protest, and the bloodshed threatened to inflame the already-fraught relationship between police and demonstrators just as the city seeks reforms.
President Barack Obama relayed his prayers to the officers and denounced violence against police as unacceptable.
"Path to justice is one all of us must travel together," Mr Obama wrote, signing the tweet with his initials to indicate that he personally composed it.
The shots were fired early today just as a small crowd of protesters began to break up after a demonstration that unfolded hours after the resignation of Ferguson police chief Tom Jackson.
The shots are believed to have come from a handgun fired across the street from the police department.
The gunman might have fired from up to 120 yards away, a long distance for most pistols. But with a line of roughly 20 officers standing in front of the building, the shooter did not have to be particularly accurate to hit two of them.
The officers were quickly released from the hospital, but St Louis County police chief Jon Belmar said they could have easily been killed and called the attack "an ambush".
A 41-year-old officer was shot in the right shoulder, the bullet exiting through his back. A 32-year-old officer was wearing a riot helmet with the face shield up. He was shot in the right cheek, just below the eye, and the bullet lodged behind his ear.
John Gaskin, a St Louis community activist, said the shooting was carried out by outside agitators intent on hijacking attention from peaceful, reform-minded protesters.
He said activists "cannot afford these kinds of incidents happening, because that gets us absolutely nowhere".