FERGUSON, United States (AFP) - Investigators are working "around the clock" and have many leads but are not close to arresting anyone over the shooting of two police officers in racially charged Ferguson, a police chief said on Friday.
Nearly 48 hours after the officers were shot just when a demonstration was ending, St. Louis County Police Chief Jon Belmar admitted to reporters: "I cannot tell you at this point that an arrest is imminent. There is certainly nobody in custody.
"When we get to the point where we feel like we have active leads, if we can do anything through you to have the community assist us, we will certainly let you know." Ferguson hit the headlines in August when a white policeman fatally shot unarmed black teenager Michael Brown, setting off protests that spread to major cities across the United States and triggered a national debate about police tactics, especially in relation to African Americans.
Last week a scathing US Justice Department report faulted Ferguson for using its police and municipal court to generate revenue by targeting the African-American majority in the St. Louis suburb of 21,000.
Wednesday night's shooting came hours after Ferguson's embattled police chief Thomas Jackson resigned. The city manager and municipal judge have also quit.
One of the police officers was hit in the face, the other in the shoulder, sparking a manhunt for those responsible and putting the flashpoint town on edge once more.
Neither police officer was seriously hurt.
Police raided a red-brick bungalow on Thursday and took in three people for questioning. They were later released and detectives Friday appeared no closer to finding who was responsible for the shooting.
"Please appreciate the fact that we have a situation where many leads come in to us," Chief Belmar said. "There were several leads that came in to us regarding that specific house. We were able to investigate that." He added: "The detectives are looking into this investigation around the clock. They will not rest until we get to the point of where we have a conclusion regarding this investigation." - 'Officers are concerned' -
Since Thursday, St. Louis County Police and Missouri's highway patrol have taken over responsibility for monitoring the nightly protests outside Ferguson's police station.
President Barack Obama condemned Wednesday's shooting during an appearance on the "Jimmy Kimmel Live" late-night TV talk show.
"What had been happening in Ferguson was oppressive and objectionable and was worthy of protest," Mr Obama said, referring to Brown's death and the findings that black Americans were targeted by overzealous policing in the town, where most of the force is white.
"But there was no excuse for criminal acts," he said.
Calls for Ferguson's Republican mayor James Knowles to resign have been growing, but he told CNN that he intends to remain in the office that he won by acclamation last year, prior to Brown's shooting.
"There are ways to remove me if that is the will of the people," Knowles said, referring to the ability for local residents to petition for the recall of a disliked elected official.
Mr Knowles told National Public Radio that Ferguson remains tense.
"Officers are concerned for their safety. Residents are concerned for their own safety right now," he said.
Separately, in the Midwest state of Wisconsin, coroners said another unarmed African-American high-school student fatally shot by police was struck in the head, torso and upper body.