Winnipeg police have issued a public plea to a woman who they believe has abducted two children.

Det. Sgt. Shaunna Neufeld spoke at a news briefing Thursday and asked Sandra Giesbrecht to get in touch with her.

A girl, who is 11, and a boy, who is 9, were last seen at 6 p.m. Monday evening in Winnipeg.

Police issued a Canada-wide arrest warrant for Giesbrecht on Wednesday.

Neufeld declined to say whether police have had any contact with Giesbrecht since the children disappeared.