Hamburg - Workers in Germany's engineering sector were on a rolling strike for a fourth day Tuesday, underlining their union's calls for an 8-per-cent pay rise.

According to the IG Metall union, hundreds of workers participated in the strikes in Mecklenburg-Vorpommern state. With the beginning of the morning shift at 5 am (0400 GMT) about 400 workers laid down work at Wadan Yards in Rostock-Warnemunde.

The union wants to expands its strikes to all of Germany, idling a number of plants for several hours, increasing pressure on employers to improve income offers.

The IG Metall union has rejected an offer of 2.1-per-cent more income in 2009 plus a one-off bonus of 1.6 per cent.

The union called it a "provocation" that the 3.6 million employees in the metal-products and electrical industry had not been offered raises to compensate for inflation.

The union expects more than 30,000 participants in Hesse, Rhineland-Palatinate, Thuringia and Saarland, 20,000 in Bavaria, and ten thousands in the north of the county.

Over the weekend and on Monday, many workers participated in nationwide protests for an 8-per-cent pay rise. (dpa)