The city’s subway system has seen increases in four major crimes so far this year, including murder and rape — as cops say they feel “handcuffed” from cracking down.

Through August, the system logged two murders and two rapes after logging only one slaying and not a single rape at the same point in 2018, according to NYPD stats set to be outlined at Monday’s MTA board meeting.

The system has also been beset by rises in robberies — from 309 to 327 — and felony assaults, which have inched up from 229 to 233 over the same time period.

The troubling tallies on the rails come despite three of those four crimes being down citywide, with a 0.2 percent hike in felony assaults the only outlier.

Hate crimes in the system have also nearly doubled this year, up 94 percent — or 62 versus 32 — through the end of August.

One high-ranking police source pinned part of the blame on Mayor Bill de Blasio for pushing a hands-off approach that de-emphasizes busts for low-level infractions such as fare-beating, even though they can uncover or discourage more serious crimes.

“The mayor has handcuffed the police in enforcing the quality-of-life crimes that we should enforce, and these guys know it now,” said the source.

“And all the fare-paying customers commuting to work have to suffer. There are people down there picking pockets and sexually assaulting them.”

Straphangers said Sunday they need no reminder.

“Every New Yorker knows the trains are dangerous, especially at night,” said Sam Wentz, who likened riding the rails to stepping into the post-apocalyptic wasteland of a “Mad Max” movie.

“It’s like the Thunderdome,” said the 62-year-old Brooklyn resident, who was catching the A train back home. “The whole system is terrible.”

Gretchen Milner, a 67-year-old Manhattan resident, agreed, pining for the days of Mayor Mike Bloomberg.

“People don’t feel safe like they used to when Bloomberg was mayor,” Milner said. “Taking the trains used to be a good experience, and now it’s just awful.”

Overall, however, major felonies in the system have declined by 2.6 percent, driven by a 6.3 percent plunge in grand larcenies — nearly outpacing the 3.6 percent city-wide drop in major felonies. Subway crime is down 1.5 percent, the NYPD said.

“The NYPD is committed to the nearly 6 million riders who use the subway each day and works closely with New York City Transit to address crime conditions,” the department said in a statement, pointing to its addition of 200 cops to its ranks this summer and the use of its neighborhood policing system throughout the city, including in transit.

“Overall crime continues to decline in the subway system and the police department vigorously investigates any incident to bring justice to victims and keep all riders safe.”

Additional reporting by Daniel Cassady and Craig McCarthy