The Canadian Union of Postal Workers is advising its members to wear protective gear in the coming days, following the gruesome discovery that at least two body parts in an apparent homicide case were mailed via the postal service.

A Canada Post employee unknowingly delivered a human foot in a box to the Conservative Party headquarters in Ottawa on Tuesday and Ottawa police also intercepted a second package containing a human hand that CBC News has learned was bound for the Liberal Party of Canada headquarters.

The discoveries, and the link to a torso found in Montreal, led Montreal police on Wednesday to caution that other body parts may have been sent by mail.

Police have issued a Canada-wide arrest warrant for Luka Rocco Magnotta, 29, in connection with the body parts.

20-year employee delivered foot package

The union is advising its members act with caution if they come in contact with such a package.

A woman who has been with Canada Post for 20 years was told Wednesday morning that she delivered the package containing the human foot.

The woman has not been identified but she was back on her route again Wednesday.

CUPW Ottawa local president Ian Anderson said the postal worker was uneasy about what other packages might be coming.

"It is on her regular route, so she has some concerns about what is going to come down in the days to come," said Anderson.

Anderson said the postal worker did not notice anything unusual when she delivered the package.