A highway maintenance worker was killed in Germany on Monday when the machine he was operating set off an explosive device, possibly a World War II bomb, AP QUOTED police sources as saying. The explosion happened as a milling machine was cutting concrete from the A3 highway near Aschaffenburg, in Bavaria. The machine was blown apart, and its operator was fatally injured. Seven vehicles on the highway were damaged by flying debris, and five people were treated for shock. «We cannot yet say whether this was an aerial bomb or something else,» Karl-Heinz Schmitt, a spokesman for police in Wuerzburg, told n-tv television. Unexploded bombs dropped in WWII raids are still unearthed regularly in Germany.