SUBWAY SLASHER

Psycho slices mom at Grand Central

Anna Martinez was viciously slashed on a subway train at Grand Central yesterday. She had changed seats to protect her baby from an erratically acting homeless woman — and the va g ra n t , Ja cqueli ne Sanj ur j o (inset), attacked her, cops said.

A homeless woman savagely attacked a mother riding the subway with her baby Sunday morning — flying into a rage because the worried victim didn’t want to sit next to her, authorities said.

The mom, Anna Martinez, 31, was slashed in the face, suffering nerve damage and requiring 30 stitches, on a 5 train approaching Grand Central station at around 11 a.m., according to police.

Martinez had boarded the southbound train with her 1-yearold daughter at 125th Street and Lexington Avenue in Harlem min- utes earlier — as did her alleged attacker, cops said.

Jacqueline Sanjurjo, 53, sat down next to the mom. But when Sanjurjo began acting erratically, Martinez got up and moved to another seat, seeking to protect her daughter, who was in a stroller, according to police.

“She didn’t want to sit next to a homeless person,” a source said.

Sanjurjo — who is “heavily addicted” to drugs, according to a relative — flew into a rage over the snub, getting up and slashing Martinez on the left side of her face with an unknown object, a police source said.

Blood soaked through a massive head bandage and streamed down Martinez’s face as she was placed into an ambulance bound for Bellevue Hospital.

Martinez’s mom, Anna Flores, broke down in tears describing what the attacker did to her daughter and how lucky it was that nothing happened to her little granddaughter.

“My daughter [was] slashed in the face, and she had her baby with her,” sobbed Flores, who showed up with her husband to pick up the little girl while Martinez was taken to the hospital. “I don’t believe this.”

Police said they were on the scene “almost immediately,’’ but

Sanjurjo was still able to flee the train at Grand Central station.

She ran wildly through the commuter hub and then onto the street and escaped, according to sources.

Police quickly broadcast her description citywide — including the fact that she was wearing a faded red short-sleeve shirt with the number 10 on it — and she was soon arrested crosstown at the Port Authority Bus Terminal, sources said.

Sanjurjo was still acting bizarrely when officers nabbed her, according to police sources.

“I’m being framed,” Sanjurjo claimed as she was being led out of the Transit Police station inside the Union Square subway station Sunday night. “Apparently, somebody is taking the blame for somebody else’s mistake.”

Sanjurjo was arraigned late Sunday in Manhattan Criminal Court on charges of assault and endangering the welfare of a child.

She was ordered held without bail due to her previous convictions, including a four-year jail stint for stabbing someone in the face with a pen.

She has been convicted of 60 crimes, mostly involving drugs, but also for prostitution and trespassing, court papers show.

A relative told The Post that she had come by his home a few days ago to ask for money.

“We know that she’s heavily addicted to drugs,” said the relative, who asked to remain anonymous. “She always told us she needs money to eat.”

Another person who lives in the Bronx shelter where Sanjurjo has been staying said she has been acting “out of her mind” lately.

Straphangers said the attack is proof that more needs to be done to combat subway crime, especially incidents involving the mentally ill.

“I hate to call [Martinez] a martyr, but [her attack is] exactly what has to happen before we can ever do something about a problem,” said Michelle Ahrens, 37, of The Bronx. “[The] reactive approach gets a woman stabbed.”

Last month, a Brooklyn woman needed 40 stitches after a homeless man slashed her from cheek to lip on an A train.

And just last week, a man crept up behind a 63-year-old woman on a train at the South Ferry station, wrapped a rag over her face and tried to rape her, according to police.

Last year, subway crime was so bad that the Guardian Angels began patrolling again for the first time in 20 years. And this year has started out even worse than 2016.

There were 112 felony assaults reported in the system from Jan. 1 through the end of April, versus 95 for the same period last year — a 17 percent increase, according to the most recent report from the MTA.

Meanwhile, arrests are down 27 percent over the same period, from 14,230 to 10,358, the report shows.

The uptick in subway crime began in 2014 and has risen since, according to city records.