BOSTON (Reuters) - Boston's mayor told Occupy protesters who have camped in the city's financial district since late September to leave by midnight on Thursday or police will take action.

The announcement came a day after a Boston judge denied the protesters' request to stop city officials from removing them.

The Boston protesters are part of a nationwide movement calling for economic justice for average Americans.

After the court ruling, Mayor Thomas Menino encouraged protesters to remove dozens of tents and stop camping in a public park in the financial district.

Authorities in many U.S. cities, often citing health and safety conditions, have dismantled camps that sprang from the first Occupy protests near Wall Street in New York.

(Reporting by Lauren Keiper; Editing by Greg McCune and John O'Callaghan)