The Missouri police officer who shot and killed Michael Brown over the weekend has yet to be identified. And while the name was expected to be released Tuesday, authorities in Ferguson, Mo., now say they won’t be identifying the officer for the time being.

Timothy Zoll, a spokesman for the Ferguson Police Department, told The Washington Post that the name won’t be released because of threats made against Ferguson police officers on social media sites.

The officer involved in the incident has been placed on paid administrative leave. There is no timetable for when police could release the officer’s name, Zoll said.

A group claiming to be associated with the hacking collective Anonymous said Tuesday that it knew the name of the officer and was working to be sure it had the right person before identifying him. This group also said it had launched cyberattacks on the city of Ferguson’s Web sites following the police response to looting on Sunday night.

Ferguson’s site and e-mail systems were both hit with cyberattacks that appeared to be continuing into Monday evening, Pam Hylton, the assistant city manager, told The Post.

The shooting of Michael Brown is being investigated by the St. Louis County Police Department at the request of the Ferguson police. Jon Belmar, chief of the county police, said during a news conference Monday that Brown was shot “several times by gunfire.”

According to police, Brown was shot following “an encounter” involving the teenager, the police officer and another person who was with Brown at the time. Belmar said that there was a struggle over the officer’s weapon inside the car and that the officer later got out and shot at Brown multiple times.

Brown was killed about 35 feet from the officer’s car, Belmar said.

Residents of the neighborhood where the shooting occurred have described the situation as initiated by a police officer, who confronted Brown as the teenager was walking down the street and then shot him as he was trying to surrender.

Benjamin Crump, an attorney for Brown’s family, has called on anyone with a recording of Brown’s death to come forward so they can find out what occurred.

“We want to know and see exactly what happened, because this family rejects what the police [and] authorities said at their press conference about how this played out,” Crump said at a news conference on Monday evening.