Police arrested 17 people, most of them members of the union representing Canada's postal workers, when they tried to cross police lines at Canada Post headquarters in Ottawa on Monday. They were charged with trespassing.

Police set up the line when officials of the Canadian Union of Postal Workers (CUPW) warned that they would storm the building looking for a document they say outlines their employer's plans for post offices and processing plants across the country.

Police arrest former CUPW president Jean-Claude Parrot outside Canada Post headquarters in Ottawa.

Canada Post has already announced it's closing a plant in Quebec City.

As television cameras rolled, the union members walked toward police lines in pairs and were quickly placed under arrest. Among those arrested was the president of CUPW, Deborah Bourque, and the former president of CUPW, Jean-Claude Parrot.

Bourque said her union has been requesting the documents for months and was left with no option but to resort to public protests to make its point.

Canada Post President and CEO Moya Greene in Winnipeg last week said the document the union wants doesn't exist.