Violent storms killed at least six people in western Germany overnight, felling trees and snarling road and rail traffic, authorities said Tuesday.

Three people died in Duesseldorf when a towering poplar tree whipped by wind, hail and rain fell on a garden shed where they had sought shelter late Monday, the fire brigade reported.

Another three people were killed in the same accident, two of them seriously.

Falling trees also killed cyclists in Cologne and Krefeld, while a 49-year-old man in Essen collapsed during clean-up efforts and later died.

Rail company Deutsche Bahn reported "serious disturbances" to its train schedule as routes were obstructed by storm debris.

Meanwhile several flights were hit by delays or cancelled at Duesseldorf airport.

The storms came on the heels of record heat over the long Pentecost weekend and were sweeping toward the northeast of the country on Tuesday.