Police continue to try to track down the suspect accused of assaulting a woman along the Waltham Riverwalk last weekend, as authorities on Friday released a police artist’s sketch of the assailant.

Massachusetts State Police and Waltham Police hope that someone will recognize the suspect and contact investigators.

Police believe that the suspect is a Hispanic male, in his late 20s or his 30s, and is about 5 feet, 7 inches tall. He was reportedly wearing a baseball hat at the time of the assault.

A woman told police that she was assaulted at around 8:45 p.m. on Sunday in the area of Newton and Farwell Streets.

The woman reported that she heard footsteps behind her and was then grabbed from behind by the suspect, who tried to put his hand over her mouth.

“The victim was able to scream and struggled to get free,” a State Police spokesperson said in a statement. “The assailant then let go of her and ran off. The woman turned and saw the assailant fleeing.”

Units from Waltham Police and State Police responded and searched the area, but they were not able to find the suspect.

“We urge the public to be aware of their surroundings and the presence of other people around them when walking in any public space,” the State Police spokesperson said. “People should carry a cell phone, don’t wear headphones, and may also consider carrying pepper spray.

“If you see anything or anyone suspicious call 911 immediately,” the spokesperson added. “If you are assaulted, if at all possible scream, make noise, and fight back.”

Police are urging anyone who recognizes this suspect or has any information about the assault to call Massachusetts State Police Troop H Detectives at 617-740-7544, the Waltham Police Department at 781-314-3600, or call 911.