A rail dispute over pay in Germany has escalated into what train operator Deutsche Bahn has called the biggest strike in its history.
Services have been sporadic in many major cities
Train drivers launched a 62-hour strike on Wednesday targeting freight trains and have now begun a 48-hour action affecting passenger services.
Regional and suburban services have been hit, with severe disruptions in Berlin, Stuttgart and Frankfurt.
Deutsche Bahn said its 10% pay offer, which unions have rejected, was fair.
The GDL union is seeking a 31% pay rise for its 34,000 workers, saying they are significantly underpaid compared to their counterparts in other leading European countries.
Thursday's stoppage - the sixth in the past three months - is the most serious yet in a dispute which German ministers have warned could do serious damage to its economy.
Deutsche Bahn, which has drafted in temporary workers to keep some services running, has said that each day of strike action would cost it 50m euros ($73m; £36m).
Only half of normal regional services were running in the west of the country while in the east, this figure was down as low as 10%.
Only a third of suburban trains were operating in Frankfurt, Germany's financial capital, and Stuttgart, while commuters in Berlin faced severe delays as only 20% of trains departed.
Traffic on city centre roads quickly built up to much-higher than normal levels.
But mainline inter-city services were less badly affected, with more than 70% of services running normally.
In a series of newspaper advertisements, Deutsche Bahn called on GDL union officials to "stop this madness".
"If we were to cave in now, the damage to the economy would ultimately be far greater," Deutsche Bahn executive Karl-Friedrich Rausch said.
"They are trying to force us to an unconditional surrender. That is not going to happen."
But union officials said management had failed to put forward an improved offer which could persuade them to return to the negotiating table.
"The Bahn management board must once and for all stop provoking strikes," GDL chairman Manfred Schell said in a statement. "We want a negotiable offer."
Train drivers are holding out for a much better deal than other Deutsche Bahn employees have received, arguing they merit a separate settlement on pay and working conditions.
In July, two other rail unions representing 195,000 workers agreed a 4.5% pay deal.