PHILADELPHIA — Philadelphia police are asking for the public's help to identify a man caught on surveillance video striking a 60-year-old woman in the face as he rode a bicycle through the city's Chinatown neighbourhood, an apparently unprovoked daylight attack that knocked the woman backwards onto the sidewalk and has left residents shaken.

Source: Philadelphia Police Department information, reported by NBC10 Philadelphia

The assault happened at about 2:45 p.m. on Tuesday, November 3, on the 1000 block of Race Street, near 10th Street in the heart of Chinatown, according to police. Investigators said the woman was walking west on Race Street when a man riding a bicycle in the opposite direction extended his arm as he passed and struck her in the face, causing her to fall backward onto the sidewalk.

The woman was taken to a local hospital and treated for facial pain and swelling, police said. Her family told NBC10 Philadelphia that she suffered swelling to her eye. She is recovering, the family said, but is concerned that the same thing could happen to someone else.

What the surveillance video shows

Police released surveillance video and still images of the man on Tuesday, November 10, as investigators work to identify him. According to police, footage captured before the assault appears to show the same man making a food delivery pickup on the 1000 block of Race Street, carrying an orange Grubhub delivery bag. In the video of the assault itself, the man can be seen sipping a drink as he rides toward the woman, then putting his arm out and knocking her to the ground.

Source: Associated Press reporting of the police release

Police described the suspect as a man wearing a pink knit hat and red Nike sneakers and riding a blue and silver bicycle. After striking the woman, he headed southbound on 10th Street, NBC10 Philadelphia reported. Police have not released a possible motive for the assault and have not said whether the victim and the suspect knew each other. The man has not been identified, and no arrest has been announced; the allegation against him rests on the police account and the surveillance footage police released.

Grubhub says it is reviewing the incident

A Grubhub spokesperson said the company is reviewing the incident. In a written statement reported by ABC News, the company said: “The safety and well-being of our customers, delivery partners and the communities we serve are incredibly important to us. We take allegations of violence very seriously and are actively looking into this matter. Our thoughts are with the person affected by this incident.”

Grubhub has not confirmed whether the man seen in the surveillance footage was making a delivery through its platform at the time, and police have not said that he was working a delivery when the assault happened — only that the footage appears to show a delivery pickup shortly beforehand, with the company's branded bag.

Neighbours say a daylight attack is hard to shake off

The attack has unsettled a neighbourhood where delivery bicycles are an everyday sight. Ken Chan, who has lived in Chinatown for 45 years, told ABC News he had never seen something like this happen in the daytime. Matt Booth, who lives and works less than two blocks from where the assault occurred, said he was shocked by the video.

Source: CBS News Philadelphia

Santiago, who works at a condominium building nearby and is 60 himself, said the attack frightened him. “I'm 60 myself, and that's a lot of concern,” he said. “I feel very scared. I got to let my residents know about this.”

What happens next

The investigation is being handled by the Philadelphia Police Department, which is asking anyone who recognises the man not to approach him and to call 911. Tips can also be called or texted to police at 215-686-TIPS (8477), or submitted anonymously online. Until the man is identified, the central questions in the case — who he is, and why a woman walking down Race Street in the middle of the afternoon was struck in the face — remain unanswered.