Investigators are probing whether the grisly knife slaying of a Barnard College student at an upper Manhattan park is connected to previous robbery patterns in the area, police sources said Thursday.

Sources also said authorities were questioning “persons of interest” Thursday morning in connection with the killing of 18-year-old Tessa Majors.

The freshman with a passion for music had been beaten and stabbed at the base of stairs inside Morningside Park near West 116th Street around 5:30 p.m. Wednesday by a group of young men who tried to rob her, sources have said.

A school security guard called police after making the gruesome discovery of Majors’ body, which had multiple stab wounds.

Sources said Majors had apparently put up a fight when the men tried to rob her.

A visiting scholar at nearby Columbia University said he was walking from the campus Wednesday night to cross the park to get home when he saw Majors lying on the ground by the stairs as police tried to help her.

“She was just lying there. Police were providing first [aid]. I didn’t want to disturb the policemen. It’s a very sad event. Awful,” said the scholar, who declined to give his name, as he placed a single rose at the scene Thursday.

Majors was rushed to St. Luke’s Hospital, where she died.

A knife was recovered at the scene, police said.

In August, a 24-year-old man was mugged inside the park, which is also close to Columbia University, cops said.

The victim in that case was walking inside the green space Aug. 23 when he was confronted by three men — one of whom pulled out a box cutter and demanded his property, police said.

The man complied and the thugs fled with $120.

Police later released surveillance images of the suspects.

Meanwhile, Mayor Bill de Blasio tweeted about the fatal attack Thursday morning, vowing, “We will find the perpetrators of this crime and bring them to justice.”

In another tweet, the mayor said that the “close-knit community at Barnard College is in shock right now.”

“We’ve lost a young woman full of potential in a senseless act of violence,” de Blasio wrote. “I want every student and every member of faculty to know your city will be with you in the days ahead.”

The mayor added that the NYPD’s presence in the area was being increased “IMMEDIATELY.”

“We will keep this community safe, arrest the perpetrators and ensure NOTHING like this can happen again,” he wrote.

Additional reporting by Khristina Narizhnaya