A man is accused of hitting his estranged wife with two cars before stabbing her with a machete in a deadly attack in the Bronx on Thursday morning, New York City police said.

Officers responding to a reported assault found 58-year-old Noelia Mateo unconscious with multiple stab wounds about 7 a.m. on Ellsworth Avenue. The woman was rushed to a hospital, where she was pronounced dead, the New York City Police Department said in a statement.

NBC New York, citing law enforcement sources familiar with the matter, reported that the attacker ran down the woman in his car and then got out of that vehicle and into the woman's car and ran over her again before attacking her with a machete. The NYPD confirmed those details and said the couple is estranged.

Victor DiChristina told NBC New York that he saw the attack and initially thought the man was trying to help the woman who was under a car, but then the man got in the car and ran over her.

After he saw the man stab the woman with the machete, which he said was about 20 inches long, "I ran over, and I'm screaming at him, trying to stop him."

"It didn't bother him at all," DiChristina said.

No arrests have been made, the NYPD said Thursday night.

Police said the attack remains under investigation.