WALTHAM (CBS/AP) — Police in Waltham continue looking for a suspect in a series of unprovoked attacks over the past three weeks. As of Sunday, no arrests have been made.

Waltham Police said they believe the same man is responsible for ten separate incidents in which men were assaulted and sometimes struck in the face or head with an object. Police have no reports of a firearm being used during the assaults.

The victims appear to be random.

The United States Postal Service said one of their letter carriers was one of the ten victims. That incident happened on the evening of November 20.

“Who will be next? I think that’s the thing that has everybody on the edge of their seat now,” said a concerned Waltham resident. “You don’t see a pattern here. You just see man after man. Who is next? Will it be me?”

Five of the incidents occurred near the same apartment complex, and another five occurred downtown. All happened after sundown.

Carmen Figueroa is a nearby gas station clerk who is friends with a man who was attacked on Wednesday night.

“This man walks up and down here every day,” she said of the victim. “It’s just hard that he can’t go from his job to his house without being assaulted. He’s the nicest person you would ever meet.

Figueroa called the attacker “a hateful person that has nothing better to do than assaulting people and just a plain coward really.”

Police are looking for this man in a series of attacks in Waltham. (Image credit: Waltham Police)

On Saturday, police released two video clips of a person they want to identify in connection to the investigation. The possible suspect, captured in the newly-released videos, is walking on Prospect Street wearing a dark coat, sneakers, and light blue pants.

The most recent attack was reported Friday night by a man who said he was hit in the face by a blunt object.

Waltham Police urged residents who live in the area to be aware of their surroundings.

“Now I have to tell my customers to watch their back while they’re pumping gas,” said Figueroa.

Police are looking for this man in a series of attacks in Waltham. (Image credit: Waltham Police)

Anyone with information is asked to call Waltham Police at 781-314-3600 or at their anonymous tip line, 781-314-3636.

(© Copyright 2020 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)