German police said on Monday that a second arson attack had taken place on a key railway line in Düsseldorf, a day after a fire in a cable duct caused major disruption on the same line, DPA reported, BTA reported.
The incendiary device used was of the same type as the one found after the fire on Thursday, police told DPA, adding that further damage had been caused to the line.
Thursday's incident closed a main railway line between the cities of Düsseldorf and Duisburg. The fire broke out in a cable duct that is part of the signalling system. Investigators believe the fire was deliberately set.
Hours later, on the left platform, "Indymedia" a letter claiming responsibility for the act was published. In it, "Angry Birds Commando" took responsibility for the crime.
"Many things would work infinitely better without the industrial system", the letter said, adding that this was why the group "caused unrest".
Düsseldorf police confirmed that authorities had also received the letter, the authenticity of which has not yet been confirmed.