The group, Lanna Action for Burma, says the country's superstitious generals, especially junta leader Gen. Than Shwe, also believe that contact with women's underwear saps them of power.
To widespread international condemnation, the military in Myanmar, also known as Burma, crushed mass anti-regime demonstrations recently and continues to hunt down and imprison those who took part.
Hilton said women in Thailand, Australia, Singapore, England and other European countries have started sending or delivering their underwear to Myanmar missions following informal coordination among activist organizations and individuals.
"You can post, deliver or fling your panties at the closest Burmese Embassy any day from today. Send early, send often!" the Lanna Action for Burma Web site urges.
"So far we have had no response from Burmese officials," Hilton said.