Germany's GDL train drivers union began a nationwide 20-hour strike on Wednesday evening until Thursday.

The labor action began at 10 p.m. (2100 GMT) Wednesday evening and will end on Thursday at 6:00 p.m.

State-owned rail operator Deutsche Bahn warned of a "massive disruption" to services throughout the country.

Deutsche Bahn advised people to postpone their trips, with spokesman Achim Stauss saying Wednesday they expect "fewer than 20 of the ICE and IC trains" to run. They are the high-speed trains that connect major German cities.

The impact of the strike will vary regionally, with some regions bracing for a complete halt in regional train services.

The labor action comes as pay negotiations between the GDL train driver's union and Deutsche Bahn break down.

What the GDL union is demanding

GDL has been demanding a salary increase of €555 ($593) per month for employees, on top of a one-off payment of €3,000 to counter inflation.

The union is also seeking a reduction in working hours without a loss of pay, from 38 hours to 35 hours.

The rail operator has offered an 11% pay increase, but GDL said that DB had made clear it was not willing to discuss the union's core demands.

DB canceled talks with GDL earlier this week, saying: "Either you go on strike, or you negotiate. You can't do both at the same time." 

DB has set up an emergency timetable and will be deploying longer trains in an attempt to balance out the reduction in service. 

For travel information, see here: https://reiseauskunft.bahn.de/bin/bhftafel.exe/dn.

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rm/sms (dpa, Reuters)