The chief of the Ferguson Police Department on Wednesday told a local television station that the officer who shot and killed Michael Brown “was hit” in the face during the encounter on Saturday.

Thomas Jackson, the Ferguson police chief, said in an interview with KMOV that the officer who encountered the unarmed 18-year-old Brown “was hit” and that the “side of his face was swollen.”

These remarks on Wednesday, four days after Brown was killed, come as residents are increasingly frustrated with the lack of information coming from police.

The St. Louis County Police Department, which is investigating the shooting at the request of the Ferguson police, held news conferences on Sunday and Monday to offer what they said happened leading up to Brown’s death. Authorities said the officer involved was “physically assaulted” and that there was a struggle over the officer’s weapon. They also said that Brown was shot “several times,” ultimately dying 35 feet from the officer’s car.

Residents and at least one eyewitness offered a different account, saying that the officer initiated a confrontation and ultimately shot Brown as he was attempting to surrender. Dorian Johnson, who said he was walking with Brown when he died, told MSNBC that Brown did not reach for the officer’s weapon or touch the officer in a threatening way.

Johnson and his attorney said earlier in the week that he had not been contacted by police. But the St. Louis County police have “made numerous attempts” to reach him, including talking with his friends and leaving a message with his attorney, but had not heard back by late Wednesday morning, police spokesman Brian Schellman told The Washington Post.

Johnson’s lawyer said Wednesday afternoon that he and Johnson would meet with both the FBI and county prosecutor later in the day.

The differing accounts and the lack of any larger update from police on the circumstances of Brown’s shooting — even as Johnson’s comments are being widely reported — are heightening the tension in Ferguson. Also raising concern among police critics: the Ferguson police reversed course on Tuesday and said they would not identify the officer who shot Brown, because of what a spokesman said were threats made against the city’s officers. (A name has been circulating in Ferguson and on social media, but it has not been confirmed by authorities.)

Meanwhile, authorities said on Wednesday afternoon that they had interviewed a dozen people in the Ferguson community and several police officers for information about the shooting.

Police in Ferguson issued a statement on Wednesday, saying that the department is “working to restore confidence” and pledging to cooperate with the ongoing investigations into the shooting.

The statement said that while police have worked to allow residents “to both grieve and voice frustrations through prayer vigils and peaceful protests,” they were asking people to only gather during the day because of the “violent outbursts” that have occurred at night.

“We ask that any groups wishing to assemble in prayer or in protest do so only during daylight hours in an organized and respectful manner,” the statement said. “We further ask all those wishing to demonstrate or assemble to disperse well before the evening hours to ensure the safety of the participants and the safety of our community.”

While there was looting on Sunday night, with stores burned and glass and debris scattered on the streets, the response on Monday and Tuesday nights was markedly different. Police used tear gas on Monday night. The following night, police faced off with residents again and had largely cleared the streets by 11 p.m. Early on Wednesday morning, police shot and critically wounded a man who aimed a handgun directly at an officer, according to the county police.

This post has been updated.

Lowery reported from Ferguson, Mo.