A U.S. rights organization says a group of jailed Burmese activists are staging a hunger strike to demand medical treatment for an injured colleague.

The Washington-based U.S. Campaign for Burma says 41 detained pro-democracy activists have been on a hunger strike since August 30.

It says they are demanding treatment for another jailed activist whose leg was broken during his arrest by Burmese police.

The rights group also is calling on Burma's military government to give Red Cross workers access to the prisoners. Authorities have barred the International Committee of the Red Cross from Burmese prisons since December 2005.

Burma's opposition says police have arrested more than 100 activists in a crackdown on recent protests around the country. The government puts the figure at around 50.

Burmese activists have held a series of rare public demonstrations in recent weeks to protest the government's decision to sharply increase the price of fuel.

Some information for this report was provided by AP.