Needles or other sharp metal objects have been found in sweets that children collected while trick-or-treating for Halloween, German police said Sunday.

Police believe most or all of the objects, which also included metal screws, were placed intentionally to cause harm.

Incidents were reported in Thuringia, Baden-Württemberg, Bavaria, Lower Saxony, and Rhineland-Palatinate, among other locations, police said.

In one of the cases in the southern city of Nuremberg, police said a child had bitten down on a needle while eating a piece of chocolate. The child was unharmed.

In two separate cases in the southwestern state of Baden-Württemberg, police said the needles had been concealed as such that they were not visible from the outside.

In several of the cases, police have opened investigations into attempted aggravated assault.

No suspects have been identified.