Ferguson resident, Blake Ashby, tries to separate Michael Brown supporters from Ferguson police supporters, outside the Ferguson Police Department and Municipal Court in Ferguson, Missouri, March 15, 2015. [Photo/Agencies]

CHICAGO - A 20-year-old man has been arrested and charged with first-degree assault and gun violations in the shootings of two police officers in Ferguson, Missouri, St. Louis County Prosecuting Attorney Robert McCulloch said Sunday.

The suspect, Jeffrey Williams, has been put on 24-hour hold on a bond of 300,000 US dollars, and the charges will include assault and firing from a vehicle, McCulloch told a press conference held in Clayton, Missouri.

The man has admitted to firing the shots and was from the general St. Louis area, McCulloch said.

However, "it was not certain if he had been targeting police," he added.

Williams told authorities he was firing at someone with whom he was in a dispute, other than the police officers, he said.

The authorities were not ruling out that other people may be charged in connection with the shootings, he said, adding that the investigation was ongoing.

The suspect was arrested on information provided by the public, the prosecutor said.

The two police officers were shot during a protest outside the Ferguson Police Department in Ferguson early Thursday morning, hours after Ferguson police chief Tom Jackson announced his resignation.

The 41-year-old officer from the St. Louis County Police was shot in the should, with bullet coming out his back; and the 32- year-old officer from the nearby Webster Groves Police Department was shot in the cheek, just under his right eye.

Authorities have offered a 10,000-dollar reward for information leading to the arrest of person or persons responsible for the shooting of the two officers.