Berlin  - Striking railway workers delayed train travel in southern Germany Thursday morning, with action expected to spread across the country.

Train workers' unions organized the strikes to underpin their pay negotiations with the state-run Deutsche Bahn.

In the Bavarian city of Nuremberg, 150 railway staff stopped work for several hours, and in Munich 60 train personnel temporarily suspended their duties.

During the course of the morning, key stations such as Cologne and Hamburg joined the strikers.

The strike action, intended as a "warning signal," has caused minor disruptions to individual services, a spokesman for Deutsche Bahn said.

Two unions representing 130,000 railway staff are demanding a 10- per-cent pay increase and restrictions on night and weekend work. Deutsche Bahn has proposed 1 per cent, but has promised to improve the offer.

The strike, which started around 4:45 am, initially led to the cancellation of around 20 trains in Nuremberg, and delays for an additional 40 services, the unions said.

Leader of the strike action, Peter Weinzierl said: "The consequences are not so serious. The railway seems to be well equipped."

The labour unions said they didn't want to disrupt services entirely, out of regard for passengers.

Alongside Munich, Nuremberg, Hamburg and Cologne, during the course of the morning the strikes are expected to target the cities of Dusseldorf, Bremen, Saalfeld, Magdeburg and the capital Berlin.

Air passengers in Germany were delayed Thursday, as flag carrier Lufthansa grounded flights at two German airports, following a walkout by flight attendants in a dispute over pay.

Lufthansa said it cancelled 70 incoming and outgoing flights at Frankfurt airport as well as 12 in Berlin during the six-hour stoppage. (dpa)