BERLIN, Germany—A union representing many train drivers at Germany’s national railway operator is calling members out on a new two-day strike starting Monday, the second round of walkouts in a bitter dispute with the company. Claus Weselsky, the head of the GDL union, said drivers of passenger trains will strike from 2 a.m. Monday to 2 a.m. Wednesday. Freight train drivers will start their strike on Saturday afternoon. The walkouts follow a two-day strike last week that brought large parts of Germany’s long-distance and commuter train systems to a near-standstill. Railway operator Deutsche Bahn “so far has shown no sign of relenting in the pay dispute it brought about itself,” Weselsky said at a news conference Friday. The union’s demands include a 3.2 percent salary increase and a one-time “coronavirus bonus” of €600 ($700). GDL is at odds with Deutsche Bahn, among other things, about when increases should take place, …