Police in Ferguson, Missouri, are looking for two men suspected of shooting and wounding a police officer, but the attack does not appear connected to last month's racial strife there after an unarmed 18-year-old black man was killed by a white police officer.
In the latest incident, authorities said two police officers were shot at Saturday night, with one of them was struck in an arm after they approached two men to investigate why they were standing outside a community center that was closed.
Two separate protests about the August 9 shooting of Michael Brown were occurring about the same time as the latest incident in the suburb of St. Louis, located in the U.S. Midwest.
But police said the shooting of the officer at the community center did not appear to be linked to the demonstrations.
On Saturday, President Barack Obama said widespread mistrust of law enforcement, exposed after the fatal police shooting in Ferguson, is corroding America.
The president, speaking Saturday in Washington at the annual Congressional Black Caucus dinner, said the corrosion affected communities that need law enforcement the most.
Obama said, "It makes folks who are victimized by crime and need strong policing reluctant to go to the police because they may not trust them."
Death under investigation
Several investigations are underway into the circumstances surrounding Brown's death.
The teen was shot by police Officer Darren Wilson and Brown's body was left in the street for hours before it was removed.
The U.S. Justice Department is investigating the practices of the Ferguson police department.
In Missouri, a grand jury is considering whether Wilson should face criminal charges.
No decision is expected before late October.
Some information for this report was provided by AP, AFP and Reuters.