(CNN) -- Canadian police say they're looking for possible connections between the discovery of severed body parts in two cities, including what appears to be a human foot mailed to the headquarters of the ruling Conservative Party.
The grisly find in an office tower in Ottawa on Tuesday came the same day that a janitor found human remains -- but not a full human body -- behind an apartment building in Montreal, about 200 km (160 miles) away.
Police also confirmed late Tuesday the discovery of a second human body part in Ottawa. No other details were immediately available.
"It would be foolish for us to disregard what is going on in Montreal," Constable Marc Soucy, an Ottawa police spokesman, told CNN. But both Soucy and Constable Daniel Fortier, his counterpart in Montreal, said there was no known connection between the incidents Tuesday night.
"'It's too soon to make any links between those two events," Fortier said.
Soucy said a hazardous materials team was sent to the office tower that houses the Conservative offices in Ottawa shortly after 11 a.m. after workers reported a suspicious package. The officers who responded noticed what appeared to be bloodstains on the box, he said.
Ottawa police Sgt. Steve Hodgson told reporters outside the office that the package had been addressed to the Conservative Party. Staffers had begun to open the package before calling police, he said.
The party, led by Prime Minister Stephen Harper, had no comment on the incident Tuesday evening.
Police are still calling the foot "possibly" human as they await tests from medical examiners, Soucy said. He would not discuss the condition of the appendage, whether any note accompanied the package or where it had been postmarked.
Ottawa's major-crimes unit is checking with other police departments for similar cases and looking back through missing-persons files for any clues, Soucy said.
"We're going to look at every avenue," he said.
In Montreal, Fortier said investigators have no reports of missing people who might fit the description of the remains found Tuesday. He said a janitor made the discovery while looking into a report of "smelly garbage" Tuesday morning, and police don't know how long the remains might have been there.
CNN's Jake Carpenter, Paula Newton and Matt Smith contributed to this report.