In what may be a first, campaigners based in Thailand have called for supporters to "post, deliver or fling" the underwear to their nearest Burmese embassy. They believe the senior members of the junta – some known to be deeply superstitious – could be made to believe they will lose their authority should they come into contact with the lingerie.

" The Burma military regime is not only brutal but very superstitious. They believe that contact with a woman's panties or sarong can rob them of their power," says the website of the Lanna Action for Burma group, based in Chiang Mai, in northern Thailand. The group says that Burmese embassies have already received underwear from people in Thailand, Australia, Singapore and the UK.

One of the group's activists, Tomoko, said: "We want to raise awareness first, and we want to target officials, letting them know we are against them abusing their power. We are sending the generals panties as a symbol of putting their power down."

What result the underwear campaign will have is unclear. Burma's senior general, Than Shwe, is known to be very superstitious. When the regime decided to move its capital from Rangoon to a new location deep in the jungle at Naypidaw, the general sought the advice of a numerologist who told him that the most auspicious time for the move would be 6.37 in the morning. As a result, the first convoy of government trucks left Rangoon at precisely that time.

News of the latest effort by activists to pressure the regime came as hundreds of Burmese riot police returned to the streets of Rangoon yesterday. The Buddhist Lent season was ending, allowing monks to move about again, and authorities feared they might spark off protests.