NEW YORK — Four people have been arrested in connection with subway slashings and assaults early Friday — a series of crimes that's sharpened the ongoing debate over safety and policing in New York City's transit system.

At least four men were wounded in the overnight attacks, all but one of which happened within a 12-minute span on the same No. 4 train in lower Manhattan, police said. Another man was punched in the face, police said. The victims were taken to hospitals in stable condition. 

Officers armed with surveillance video and descriptions of the suspects intercepted them as they exited a northbound No. 1 train at the 79th Street station in Manhattan, Chief Jason Wilcox said.

The men, whose names have not been made public, was taken into custody without incident, Wilcox said. One of them was out on his own recognizance after a January arrest for a knifepoint robbery that Wilcox said was "eerily similar" to the subway assaults.

A fifth man whom investigators believe was also involved in the attacks remained at large as of Friday afternoon, he said.

"We are confident that we have the right people in custody," Wilcox told reporters at a news conference outside a Manhattan subway station.

The attackers, sometimes splitting into groups of two or more, started accosting passengers on a southbound No. 4 train, carrying out three attacks between the Union Square and Brooklyn Bridge stations, police said.

In the first attack, around 4:20 a.m., police said three to five suspects approached a 44-year-old man, and slashed him on the left cheek. The attackers fled the subway car and the victim flagged down officers when the train reached the Union Square station.

About five minutes later, as the train approached the Astor Place station, the men attacked again, slashing a 40-year-old man in the nose and punching a 41-year-old man who may have tried to intervene, Deputy Inspector Steven Hill said.

The suspects then approached a 44-year-old passenger near the Brooklyn Bridge station, slashed him on the left cheek and took his wallet and cell phone, Hill said. 

About 30 minutes after the first wave of attacks, a 48-year-old man approached police officers at a subway station near Yankee Stadium in the Bronx and said that he'd been slashed in the right eye while aboard a train near 59th Street—Columbus Circle station in Manhattan, Hill said. That man was listed in stable condition and was undergoing surgery, Hill said. 

The assaults happened amid growing concerns about crime on the city's subways as ridership picks up from pandemic lows, though it's still averaging about 40% below normal. 

The city says it's assigning 500 more police officers to tackle subway crime, but the transit officials have been urging Mayor Bill de Blasio to do more.

NYC Transit's interim president, Sarah Feinberg, accused the Democratic mayor Friday of "negligence on the issue."

"Enough is enough. The mayor is risking New York's recovery every time he lets these incidents go by without meaningful action," Feinberg, whose agency doesn't report to de Blasio, said in a statement. 

De Blasio spokesperson Bill Neidhardt accused the MTA of finger-pointing and urged it to "get with the program." 

"We're going to keep putting massive resources into this fight to keep our subways safe," he said in a statement.

Police Commissioner Dermot Shea, speaking to reporters Friday afternoon, underscored the increased police presence in the subway system and the quick work by officers to arrest the suspects in Friday's attacks.

"You have one of these incidents, it's too much," Shea said.