Police have arrested a 20-year-old man for allegedly stabbing an MTA conductor multiple times in the Bronx this weekend.

The incident occurred on the platform of the 149th Street-Grand Concourse station just before 11 a.m. on Sunday. Police say Walter Rivera, 20, approached the conductor in front of the Manhattan-bound 4 train and stabbed him four times in the abdomen and shoulder.

The wounded conductor, with the help of a second MTA employee, managed to apprehend the attacker until police arrived, according to the Transit Workers Union Local 100. Rivera was charged with assault and criminal possession of a weapon—a knife that police officers recovered at the scene.

The 33-year-old victim, whose name has not yet been released, has worked for the MTA for five years, the union said. He was transported to Lincoln Hospital and is in stable condition.

"We demand that the full weight of the law now come down on the individual arrested for this attack," TWU President Tony Utano said in a statement. "We also demand that the city step up and make the subway safer for both workers and riders. We want to go to work and return to our families safe and sound."

Utano's statement also said that according to initial reports, "the attacker is an emotionally disturbed person. Too many of these unfortunate people use the subway system for refuge, and some of them pose a serious threat to workers and passengers, as it appears was the case this morning. The city is failing to address some very serious social issues, and it falls well short of its responsibility to move these people from the subway system to proper shelters where they can receive the care and treatment they need."

This past summer, the transit union warned that misdemeanors and felony assaults against subway workers have been steadily rising for the last few years. Earlier this month, two female MTA workers in the Bronx—a subway conductor and bus driver—were attacked with an unknown liquid believed to be urine. The individual responsible for those attacks has not yet been arrested.

Some MTA employees will march to the authority's headquarters on May 3rd to demand further action be taken to stop violence against transit employees.

"This wasn’t an assault on the conductor, it was an attempted murder," Tramell Thompson, an organizer of the march and MTA conductor, told Gothamist. "Let’s not water this down."