Police in Canada have found the bodies of four people, including an infant, in a snowy field near the US border.

The group died from exposure due to the frigid cold, which dropped to -35C (-31F) with wind chill, officials say.

The bodies of a man, a woman, a teenage boy and an infant were found near Emerson, Manitoba, on Wednesday.

The identities and nationalities of the dead are not yet known. They are believed to have been attempting to cross into the US.

Manitoba Royal Canadian Mounted Police (RCMP) Assistant Commissioner Jane MacLatchy shared the discovery with reporters in a news conference on Thursday.

“What I am about to share is going to be difficult for many people to hear,” she said, calling it “an absolute and heartbreaking tragedy”.

Around 09:30 local time (15:30 GMT) on Wednesday, Canadian police were alerted that a US Customs and Border Patrol team had arrested a group that had crossed from the area, which is a known illicit border crossing site.

A US official told the Canadian team that one man was discovered with items for an infant, but that no child was found with him.

A search was launched on both sides of the US-Canada border, and the group was discovered around 13:30 about nine to 12 metres from the US border. Crews using snowmobiles and all-terrain vehicles continued to search the deep snow until late Wednesday evening.

Referring to the group, Ms MacLatchy said that they may have been left by somebody “on their own in the middle of a blizzard when the weather hovered around -35”.

“These victims faced not only the cold weather but endless fields, large snowdrifts and complete darkness.”

She also called on “anyone who’s thinking of crossing the border in Manitoba, either heading south or north: just don’t do it.”

“Do not listen to anyone who tells you they can get you to your destination safely. They cannot. Even with proper clothing it is not a journey that is possible.”

So-called “irregular” crossings from the US into Canada – crossings outside official border points – increased drastically around 2017, a phenomenon driven by multiple factors including immigration policies put in place by former US president Donald Trump.

Canada banned such crossings at the beginning of the pandemic, with officials turning asylum seekers back to the US. The ban was lifted in November.

Local officials in Emerson say it is rare to see people crossing from Canada southbound into the US.