OAKLAND (CBS SF) — Thousands of Oakland city workers are set to go on strike Tuesday.

Two labor unions, SEIU Local 1021 and International Federation of Professional and Technical Engineers Local 21, have informed the city of their plans to strike. The unions represent nearly the entire city civilian workforce.

Police and fire personnel will not take part in the strike but it’s unclear what other city services might be affected by the work stoppage.

The same unions participated in a half-day strike in early November, shutting down Oakland libraries, senior centers, child care programs and other city offices.

The two sides have been in contract negotiations for more than six months.