The statement came after detectives reviewed hundreds of hours of video over a day and a half as they tried to solve what they were calling a possible hate crime. A police spokesman, Howard Ludwig, said the department had also received calls on its tip line, but it was too early to tell whether they were credible.

Smollett, who is black and gay, and an outspoken activist on social issues, told police that around 2 a.m. Tuesday, he had been attacked on the street while heading back from a late meal by two masked men directing racist and homophobic slurs at him. The men also put a rope around his neck, he told police, and poured a chemical substance on him.

Anthony Guglielmi, a police spokesman, told the Chicago Sun-Times that Smollett had been hesitant to call police because of his status as a public figure, and that his manager was the one who made the call 40 minutes after the incident. When police arrived at the apartment where Smollett was staying, a “thin, light rope” was still around his neck, Guglielmi said. At the urging of police, Smollett was taken to a hospital for lacerations on his face and neck, and was treated and released.

In a second interview with police Tuesday, Smollett said one of the men yelled, “This is MAGA country,” referring to President Donald Trump’s campaign slogan, “Make America Great Again.”

Initially, police had been stymied, finding nothing useful on surveillance video despite the fact that the neighborhood, Streeterville, filled with office buildings, hotels and luxury apartments, had a “very high density” of cameras. Then, on Wednesday, police announced they had “located a surveillance camera that shows potential persons of interest wanted for questioning.”

“While the video footage does not depict an assault, the individuals pictured are seen in the vicinity of the alleged criminal incident during the alleged time of occurrence,” the police statement said.

Police released images showing two figures walking down a street; their faces were hard to distinguish because of the camera’s high angle. Police asked for the public’s help in identifying them “in order to determine whether they may have any involvement in the reported incident, or if they may have witnessed the incident.”

The furor surrounding the case continued to grow Wednesday. Rep. Bobby Rush, D-Ill., wrote a letter to FBI Director Christopher Wray, calling for “an immediate and sweeping civil rights investigation into the racist and homophobic attack on Jussie Smollett.”

The bureau is already investigating a letter sent to Smollett at “Empire” production offices in Chicago last week that contained threats toward Smollett and a white powdery substance. The FBI did not return a request for comment Wednesday.

On Tuesday night, after the closing curtain, the cast of the Broadway musical “Choir Boy” read a statement in support of Smollett.

This article originally appeared in The New York Times.