BERLIN (AP) — Police in Germany halted a shipment of self-propelled howitzers for the U.S. Army after determining they lacked proper documentation and had been loaded on unsuitable trailers.

They said the howitzers were being loaded onto replacement vehicles Thursday two days after a police patrol stopped the trucks carrying them near the town Bautzen, not far from the Polish border.

Saxony state police say an examination of the convoy of six M 109 howitzers showed the shipment lacked the necessary paperwork and that the load was both too wide and two heavy for the trailers.

In addition, they say the convoy lacked the necessary accompanying vehicles and that some drivers had been driving for longer than legally permissible.

Police said it’s up to the private transport company to resolve the problem.