Police are investigating after a man says he was assaulted by four men who allegedly took off with the dog he was walking in Derrydowns Park on Monday.

Dan Valle said he was walking his girlfriend's dog Charlie in the park, located near Jane Street and Finch Avenue, when they were approached by four men.

The alleged victim said the men dismounted their bikes and asked him what he was doing in the park.

The man said when he told the group to leave him alone, one of the male suspects punched him and another pulled out a knife.

“I didn’t know if there was intent on using the knife but it was definitely there," Valle told CTV News Toronto on Tuesday. "I saw the knife and another guy came and swung a punch, hit me in the face and I kind of fell down a bit. As soon as I fell, I felt the leash yanked out of my hand.”

The suspects reportedly took off with the dog and were last seen heading toward Finch Avenue.

“I started running immediately," he said. "I saw my bag in the middle of the grassy area and they took off heading toward Finch Avenue from what I saw.”

Valle said Charlie, who is a four-year-old Shih Tzu Pomeranian mix, has long shaggy white fur and was wearing a black harness and a blue Maple Leaf sweater.

Darlin Castillo, Charlie's owner, said she just wants her pet to come home.

“If they’ve ever been a pet owner, they would understand the relationship with their pet," Castillo told CTV News Toronto. "It’s not fair to us, it’s not fair to her. For whatever reason, if this is a cruel joke, it’s just not funny.”

Police told CP24 Monday that they are investigating the incident but added that they have not found the suspects or the dog.

They said they're looking for four suspects in connection with the incident.

All four suspects are described as being black males who are between 20 and 25 years old.

The first suspect is described as being unshaven and having a medium build. He was last seen wearing a red baseball hat with no logo, a red windbreaker-style jacket and riding a black mountain bike. Police allege this suspect punched the victim.

The second suspect is described as having a medium build, wearing a navy blue jacket and riding a black mountain bike.

The third suspect was last seen wearing a black hooded sweater, a red Canada Goose vest and black pants. Police said the third suspect was also riding a black mountain bike and was carrying a knife.

The fourth suspect is believed to be wearing a light-coloured sweater and riding a black mountain bike.

Anyone with information is being asked to call police at 416-808-3100 or Crime Stoppers anonymously at 416-222-TIPS (8477).