Philadelphia police are investigating an encounter in North Philadelphia last week in which a white officer temporarily placed a young black man in the back of a police cruiser, then said, “Remember you were shaking in the police car,” when the officer let him go.

Two videos of the incident were posted on Twitter over the weekend and have been widely shared. As of 1 p.m. Monday, the videos had been viewed more than 1.5 million times.

Capt. Sekou Kinebrew, a police spokesperson, said in an email Monday that the department’s Internal Affairs bureau was investigating the encounter, which took place about 3:25 p.m. Thursday near 23rd Street and Cecil B. Moore Avenue.

“We take matters involving the stopping, detainment, and investigation of citizens very seriously,” Kinebrew said. He declined to comment further, but encouraged anyone who witnessed the interaction to reach out to Internal Affairs.

It was not clear what led to the encounter. The first of the videos begins with the unidentified officer holding the young man’s arm and guiding him into the backseat of a police SUV.

The Twitter user — who did not respond Monday to a message from an Inquirer reporter — wrote that she had been waiting for a bus with a group of teens when several police officers showed up.

A short time after the teen had been placed in the van, the officer who put him in the backseat can be seen speaking with him before letting him get out. As the teen walks away, the officer says: “Remember you were shaking in the police car.”

Michael Coard, a Center City defense lawyer, said in an email that he had been asked by “several ministers, community organizations, and social media contacts (as well as a city official)” to look into the incident. He did not identify the city official.

Coard said he agreed to do so because he believed the incident was “at best, a case of racist ‘bullying with a badge’ on steroids and, at worst, a case of conspiratorial ‘stop and frisk and kidnap’ involving not just the thuggish male cop but the two criminally collaborating female cops.”

Hans Menos, executive director of the Police Advisory Commission, said that although he did not know what precipitated the encounter, the officer, through his behavior, could have “delegitimized” himself — and possibly police in general — with the witnesses.

“Somebody who had the opportunity to be professional … instead decided to tease somebody who’s younger than him, and that’s what bullies do,” Menos said.

John McNesby, president of Fraternal Order of Police Lodge 5, called it “ridiculous” that the videos had become a magnet for criticism and said they did not show why the officers had been called in the first place.

“Obviously, there’s a reason why they were there, and then it’s called an investigation,” McNesby said. “It’s police work.”

He said critics should channel their concern toward issues such as ongoing gun violence, instead of what he described as “police doing normal police work in the city of Philadelphia.”