School support workers are also taking to picket lines in a protest about pay.
The latest industrial action comes as legislation is to be debated which could lead to the restoration of the Northern Ireland Assembly and Executive in the coming days.
The UK government has committed funding to cover public sector pay deals if Stormont returns but unions have not called off the strike.
5.
Tranlink workers continue their industrial action with a one day strike. Photo: Jonathan Porter / Press Eye
6.
Transport workers and UNITE union members take strike action this morning Photo: stephen davison
7.
Trade union strikes have brought public transport to a standstill on Thursday. Photo: presseye
8.
Traffic chaos on the Castlereagh road during this mornings rush hour into the city. Photo: pacemaker