Two people were found stabbed to death at two different points on the A line overnight Friday, police said. The MTA is asking for increased visibility from the NYPD across the system while police investigate the two deaths.

The first incident was reported at around 11:20 p.m. on Friday at the Mott Avenue and Beach 22nd Street station in Far Rockaway, where the A subway line begins and terminates. There, NYPD transit officers from within the 101st Precinct found a man sitting on a bench inside a subway car “unconscious and unresponsive” with stab wounds to his neck and body, according to police. The man was pronounced dead at the scene.

Two hours later, at the other terminus of the A line at the West 207th Street and Broadway station, police received a 911 call of a woman found unconscious inside a northbound subway car. There, transit officers found the woman with stab wounds throughout her body, according to the police. The victim, 44, was discovered “laying under a bench” inside the subway car and was declared dead. The body had been discovered 20 minutes after the entire system shuts down so crews can begin cleaning subway cars. Her identity has not been disclosed pending notification.

Calls to improve the safety on the subways have gone out for months, with Mayor Bill de Blasio promising stepped-up NYPD presence on subway stations after a series of shoving incidents by straphangers. In recent weeks, more assaults have been reported, prompting the union to call for greater police presence.

In a joint statement, New York City Transit interim president Sarah Feinberg and Transit Workers Union president Tony Utano re-emphasized that greater police presence is needed.

“We have been calling on the city to add more police to the system, and to do more to assist those who desperately need mental health assistance,” Feinberg and Utano said in a joint statement. “The time for action is now. We are demanding that additional resources be put into the system to address this challenge immediately. Our hearts go out to the victims, as we cooperate with active investigations and urge prosecutors to pursue maximum penalties for perpetrators."

It’s unclear whether the two homicides are related. The NYPD is still digging into the two cases.