WINNIPEG -- Police in Winnipeg are advising the homeless to use caution in the wake of two homicides, and are asking other citizens to pay special attention to make sure the homeless are safe.

Police say the bodies of two men who both lived off the streets were found on Saturday behind buildings in the downtown area.

Sgt John O'Donovan told a news conference on Sunday that while autopsy results are still pending, the similarities between the two deaths makes police believe the cases are related.

"You can trust me, it was not a simple killing," O'Donovan said.

Investigators say the body of an older man was found early Saturday morning, and the second body was found later in the day about a block away.

Police say they believe one suspect is responsible for both deaths.

Police have released pictures taken from surveillance video of a male O'Donovan said was in the area at the time and may have information about the case. He said police are trying to identify and speak with him, as well as two other people who were seen near a construction trailer in the area.

O'Donovan said investigators also haven't ruled out the possibility the cases may be linked to the death of a homeless man in the city on April 10th.

"If you're a person who lives on the streets and you happen to see this broadcast, you know what to do to stay safe and survive. Stay with your friends -- there's safety in numbers. Don't wander off with someone you don't know," O'Donovan said during the news conference.

"These vulnerable people, they're a part of our community and it's all our responsibility to keep them safe."

O'Donovan said one of the victims was homeless, while the second man lived a similar lifestyle but did have a home.

The identities of the victims has not been released.

O'Donovan said investigators have been reviewing a lot of surveillance video for clues, and that businesses have been helpful providing it.

He asked all people in Winnipeg to help protect the city's vulnerable population. He said if it's safe, take cellphone video of anything suspicious.

"They're often invisible, but make sure they're safe and they're not being harassed by anybody or appear to be in a disadvantaged position with someone," O'Donovan said.

They are asking homeless people and those who frequent the streets to avoid secluded areas and, if possible, walk with others.

Police say autopsies and family notifications are pending.