Officials in suburban Detroit appealed for patience and calm Thursday while investigators review why police repeatedly punched, kicked and Tasered an unarmed black driver who ran a stop sign.

The Jan. 28 confrontation in the small city of Inkster drew about two dozen protesters affiliated with the Rev. Al Sharpton’s National Action Network to police headquarters Wednesday — following NBC station WDIV ’s broadcast of a dashcam video of the arrest. Sharpton is the host of MSNBC’s “PoliticsNation.”

“Why you beating on me like this?” the driver, Floyd Dent, 57, asks after police pull him to the hood of a cruiser.

Inkster Police Chief Vicky Yost told reporters Thursday that state police are investigating the arrest. She declined to discuss details about the case or the officers, who have been reassigned to administrative duties.

“It’s important that the investigation takes its course,” Yost said. “It needs to be independent. It needs to be thorough.”

Charges against Dent of resisting arrest and assaulting a police officer were dropped. He is still due in court Wednesday on a charge of possession of cocaine.

Accounts of the incident from Dent and from Inkster police — all of whom in the video appear to be white — are wildly different:

Police said Dent attempted to flee the police car, but the video appears to show Dent maintaining a consistent speed and then pulling over safely across the street from a police station.

Police say Dent threatened to kill the officers. Dent says he didn’t — and none of the six officers’ microphones were turned on at the beginning of the incident to substantiate their claim.

One officer said Dent bit him on the arm. Dent said he didn’t, and the officer didn’t seek medical attention or photograph his injury to support the allegation.

Police said they found a bag of crack cocaine under the passenger seat of Dent’s car. Dent, who has worked for Ford Motor Co. for 37 years and has no criminal record, said officers planted the cocaine. A post-arrest blood test showed no drugs in his system.

A judge dismissed all charges involved in the physical confrontation with police after watching the video obtained by WDIV. Dent’s lawyer said he was offered a plea deal resulting only in probation on the cocaine possession charge, but Dent turned it down, telling the station he wouldn’t plead guilty to a crime he didn’t commit.

“I can’t even watch the tape of them beating me, because I get upset,” Dent told the station this week.

Yost said that “appropriate action” would be taken if the investigations found the cocaine possession charge to have been manufactured.