NEW YORK (CBSNewYork) — Police are searching for a man seen on video shoving another man onto the subway tracks in Brooklyn.

It happened around 11:30 a.m. Sunday at the Atlantic Avenue station.

Police said the suspect got into an argument with the 29-year-old victim on board a northbound 4 train as it approached the station.

When the men got off the train, police said the suspect pushed the victim off the platform and onto the southbound tracks.

Surveillance video shows a woman confront the suspect. He takes a swing at her before walking away.

Police said the victim pulled himself back onto the platform and refused medical attention.

Mayor Bill de Blasio said Monday the city is stepping up efforts to keep subway riders safe.

NYPD is going to be increasing its presence in the subways, that will be very visible. We continue to expand our mental health efforts. The thing we’ve got to do is find people and get them help before something like this happens, and we need medical intervention, which our city agencies will do,” said the mayor.

MORE: Pushes, Punches, Slashings: With Violence Getting Out Of Control On NYC Subways, Guardian Angels Step Up To Patrol

The past week saw a string of crimes in the subway system. A shocking caught-on-camera push at the 14th Street/Union Square station grabbed the most attention.

During Thursday’s incident, the female victim was lucky to survive after a homeless man allegedly ran up and shoved her on to tracks just as the train rolled in.

Hours earlier, there was another push onto tracks that injured a man.

There were two attacks Tuesday. A man sucker-punched Broadway actor Alex Weisman inside the 103rd Street station, seriously injuring his eye.

And another suspect is being hunted by the NYPD, which said he punched the face of a 65-year-old Metropolitan Transportation Authority worker inside the 23rd Street station.

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Slashings followed on Saturday. A 53-year-old man was slashed on the face on a 4 train approaching Grand Central Terminal. Hours earlier, a knife-wielding man attacked a 26-year-old man inside Brooklyn’s High Street station, police said.

The attacks prompted new patrols by members of the Guardian Angels. The group announced it’s back in a big way Sunday.

“I’ve never seen as many emotionally disturbed persons having episodes as we see now,” Guardian Angels President Curtis Sliwa told CBS2’s Dave Carlin.

Anyone with information about the incidents is asked to call the NYPD’s Crime Stoppers hotline at 1-800-577-TIPS (8477), or for Spanish, 1-888-57-PISTA (74782). You can also submit a tip via their website or on Twitter, @NYPDTips. All calls are kept confidential.