This story has been updated.

Shots were fired early Wednesday morning near the scene of a Minneapolis protest for the second night in a row. One man was arrested, but there were no reports of injuries, police said.

[Two men arrested in shooting of Black Lives Matter protesters in Minneapolis]

As The Washington Post reported, Black Lives Matter protesters have been camping out in front of Minneapolis’s Fourth Precinct since Nov. 15, when two of the city’s police officers were involved in the killing of 24-year-old Jamar Clark.

On Monday night, five people suffered gunshot injuries that were not life threatening when at least one person opened fire on the crowd. Within 24 hours, police had three people — all white men — in custody: A 23-year-old arrested in Bloomington, a nearby city, as well as a 26-year-old and a 21-year-old who turned themselves in to investigators. A fourth person, a 32-year-old Hispanic man arrested in south Minneapolis, was released after it was determined he was not at the scene of the shooting, police said.

By Tuesday night, all seemed peaceful. Not long before the shooting, the Star Tribune posted video of those celebrating “love for the community,” as one demonstrator put it.

At around 12:40 a.m. Minneapolis time Wednesday, that changed. An officer who answered the phone at the Fourth Precinct confirmed that shots were fired and said that there were no injuries or arrests. There were no details about who fired the shots at whom, or why.

At around noon, police spokesman Scott Seroka e-mailed this statement to The Washington Post: “The MPD did respond to a shots/shotspotter activation in the area near the 4th precinct at 12:40 am. (Near 1300 blocks Newton/Morgan). No reports of injuries. Suspects stopped and id’d by officers. One male booked.”

While the Associated Press and other outlets reported that all was quiet overnight at the protest, demonstrators took to social media to discuss the gunfire. Alternative news outlets such as Unicorn Riot also noted the shots; one posted video.

After the volley, protesters were urged to take cover.

“Everybody get down!” someone shouted. Another responded: “F— this laying down s—! Let’s shoot back!”

The Fourth Precinct said no arrests were made. After the shooting, police combed the scene for bullets.

Several people involved in the demonstrations — including a Black Lives Matter organizer and the NAACP Minneapolis chapter president — have called the alleged gunmen who attacked Monday night white supremacists. Authorities, however, have not confirmed those claims — and it was unclear who had opened fire early Wednesday.

On social media, the attacks were swiftly condemned.

“SECOND TIME IN TWO NIGHTS PROTESTORS HAVE BEEN SHOT AT,” one person tweeted. “CALL THIS WHAT THE F— IT IS. TERRORISM.”

After Clark was killed on Nov. 15, police said that he was the suspect in an assault and interfered when paramedics tried to treat the assault victim.

“At some point during an altercation that ensued between the officers and the individual, an officer discharged his weapon, striking the individual,” the Minnesota Department of Public Safety said in a statement.

The officers involved were Mark Ringgenberg and Dustin Schwarze. According to the Bureau of Criminal Apprehension — the state agency investigating the shooting — they have both been with the Minneapolis police for a little more than a year, and both have been officers for seven years. Police have not said which officer fired the fatal shot.

The FBI has announced that it will conduct its own investigation, while the U.S. attorney’s office in Minnesota and Justice Department prosecutors will review evidence to see whether any civil rights statutes were violated.

Some witnesses said Clark was handcuffed when he was shot, while police said that did not appear to be the case. Drew Evans, superintendent of the Bureau of Criminal Apprehension, said that authorities were still working to determine whether Clark was handcuffed when he died.

Demonstrators called on police to release video footage of the shooting. Evans said that there is no complete video of the shooting, though investigators have multiple videos that he said are related to the encounter.

Social video shows the Black Lives Matter protest where five demonstrators were shot late on Nov. 23. Police are searching for three white male suspects involved in the shooting, which took place near the Minneapolis Police Department's 4th Precinct. (Jenny Starrs/The Washington Post)

Michael E. Miller, Mark Berman and Wesley Lowery contributed to this report.