Claver was one of many coastal towns that for some time were ignored after the American and Filipino military forces surrendered to the Japanese in May 1942. Claver became the headquarters of the 114th Infantry Regiment of 10th Military District, which was the guerrilla organization under the jurisdiction of the United States Army. Some residents had fled for fear of a Japanese raid or occupation of the town, but an American whose family took refuge there said Claver still had a feeling of normalcy to it. On a hill above town the guerrillas maintained a radio station by which they kept in contact with other military units. The radio operator decided, without the knowledge of his superiors, to jam wavelengths used by the Japanese. The Japanese got a fix on the location of the station as a result.