NEW YORK (CBSNewYork) — Violence is once again plaguing the subway system.

Police said four new random attacks happened Wednesday, all before lunchtime.

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The victims were either punched or slashed. The assaults are raising more questions about safety in the Big Apple’s underground, CBS2’s Dave Carlin reported.

One of the victims was a Metropolitan Transportation Authority employee identified by her union as supervisor Andrea Vasquez. She was on duty on the platform inside the Times Square station at around 7:45 a.m. when police say she was punched in the face by a female stranger, who fled.

“Any attack on an MTA worker is unacceptable. We have a lot of police in the subways. They have proven that God forbid anyone commits an act of violence, they will be found, they will be prosecuted, they will suffer the consequences,” Mayor Bill de Blasio said.

Another random attack happened in the same station about 90 minutes later. Investigators said a male suspect approached a 35-year-old man who was sitting on a bench, spit in his face and then slashed him with a sharp object before fleeing the station.

The back-to-back crimes in a single station worried Treazer Maina, who works for a Times Square-based sightseeing bus company.

“The police should do something about the security. They should tighten their security a lot,” Maina said.

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As police responded to the pair of Times Square station incidents, a 21-year-old woman was punched in the face in Queens while on an F train at around 8:30 a.m. at 75th Avenue, Carlin reported.

The suspect, a 29-year-old man, was arrested after riders pinned him down, police said.

Then at around 10:30 a.m. in Brooklyn, a woman was stabbed by a man inside Pennsylvania Avenue station in Brownsville.

The woman is expected to live, but her attacker got away, Carlin reported.

Commissioner Dermot Shea said the NYPD understands the public’s concern.

“So there are large amounts of officers on a daily basis, but there’s always more to do. And if one New Yorker doesn’t feel safe because of any number of circumstances on the subway, we have to do more,” Shea said.

The mayor said one way to fight this surge in crime is to encourage more people to come back to tourist spots and subways, because criminals lose opportunity and the upper hand when masses of law-abiding citizens are everywhere.

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Wednesday’s incidents came in the shadow of a shooting in Times Square, and a series of subway crimes that have New Yorkers on edge.

Dave Carlin