Sömmerda (dpa/th) - An anonymous letter with a bomb threat triggered a major police operation at the Sömmerda district court. The building was cleared on Tuesday morning and the access roads to the court were largely blocked off, the police said. Officials then searched the property with two service dogs, but no evidence of explosives could be found. The blocking measures were lifted again in the early afternoon, it said. The criminal police began investigations into disturbances of public peace through threats of criminal offences.