Security has been heightened as police search for the man who attacked an off-duty ambulance worker in Brooklyn.

The off-duty medic volunteer with Hatzolah, a private EMS organization that serves Jewish communities, was walking at Eastern Parkway and Rogers Avenue in Crown Heights when he was attacked from behind around 8:30 p.m. Tuesday.

“He was screaming, ‘I’ve been stabbed! I’ve been stabbed!’” a witness said. “Police showed up like a minute later and right away closed the whole scene.”

The 34-year-old victim can be heard in radio transmissions frantically calling his colleagues for help.

“I’ve been stabbed,” he says.

Cellphone video shows the man being tended to by his fellow medics in a Hatzolah ambulance shortly after the attack.

According to police, the victim said his attacker was wearing black sweatpants, a black hoodie and what was described as a white hockey mask. He said nothing before slashing the victim’s right shoulder and then running east down Eastern Parkway, police told CBS2’s Janelle Burrell.

The victim, who was not wearing his uniform, told police that he did not know his attacker and that it was completely unprovoked.

The victim is expected to make a full recovery. Police said he was not seriously injured.

So far, police said there is no indication as to whether the attack was a hate crime, though it is being investigated as a possible one.

Police spent the overnight and early morning scouring the area for evidence as they try to find the suspect. Extra police officers were on patrol Wednesday morning near Eastern Parkway, and fliers had been posted asking for tips about the case, Burrell reported.

The incident left neighbors concerned.

“It’s terrible, you have to watch and you have to be careful; wherever you go you have to look around,” Rabbi Sholom Gorodetsky, who knows the victim, 1010 WINS’ Carol D’Auria.

“It’s never good to hear that where you live there’s a possibility of crime happening so close to home, so I’m kind of in shock, too,” said Shaunee Morgan.

“It doesn’t shock me ’cause this is New York, but around here, it doesn’t really happen,” said Darren Paterson.

“We’re very concerned in the neighborhood because people they’re walking there, and it’s kind of disturbing,” one man said. “I know what’s being done about it, but I think it deserves a lot of attention.”

In another possible anti-Semitic attack in Crown Heights, police say an Orthodox Jewish man was assaulted on his way to synagogue at 5:45 a.m. Wednesday morning.

The incident happened outside 645 Lefferts Ave. The victim was punched in the face and suffered a bloody nose, police said.

While being arrested, the suspect told cops he was fed up with the Jews and was sending them a message, police said.

Charges against the man are pending.

At this point, police don’t believe the incidents are related, D’Auria reported.