Ukraine has formed eight new “storm” brigades to take part in a future counteroffensive amid growing speculation about its timing and whether it can inflict serious defeats on Russia. The Ukrainian interior ministry said it had “fully formed” initial brigades comprising up to 40,000 troops, but they would need further training before being ready to fight. An explosion derailed a freight train for the second day in a row in a Russian region bordering Ukraine on Tuesday, sending both the locomotive and some cars off the tracks, authorities said. It occurred in the western Bryansk region, which borders both Ukraine...