Workers picketing in Belfast

Talks between the trade union NIPSA and management have so far failed to make progress.

Friday's action mostly affected MOT centres and vehicle tax offices.

The government has imposed a pay package which will add 3.67% to the wage bill of the Northern Ireland Civil Service.

However, union officials say that was part of a pre-agreed increment and takes no account of the rise in the cost of living.

Latest phase

The action is the latest phase in a campaign of strikes aimed at causing maximum disruption and at putting pressure on civil service bosses and ministers.

All union members have been maintaining a strict work-to-rule across all departments.

In another development, selective strike action by small groups of civil service staff will force two meat factories in Ballymena and Crumlin, both in County Antrim, to close next week.

More than 20 veterinary and meat inspection staff in the Department of Agriculture and Rural Development are due to start extended strike action next Tuesday.

Representatives from the meat industry say they are hopeful the situation can be resolved soon.