Tens of thousands of Taiwanese gathered in downtown Taipei on Saturday to protest the death of a 24-year old soldier confined to a brig as punishment for bringing an unauthorized cellphone onto his base.

The protest was the biggest so far in the continuing campaign to register discontent over the death of Hung Chung-chiu on July 3.

The simmering anger is complicating the Taiwanese military's efforts to transition from a mixed forced of conscripts and volunteers to an all-volunteer force.

The university graduate died after several days of being forced to perform a rigorous regime of push-ups, sit-ups and other exercises in sweltering heat. He was just three days short of completing his 20-month service obligation at the time.

Eighteen officers and NCOs have already been charged in connection with the case. President Ma Ying-jeou has apologized and the minister of defense has resigned.

Taiwan's ambitious military transition is scheduled to be completed by 2015. But even before Hung's death, recruitment goals were not being met, hampered by the military's generally low repute among large swathes of Taiwanese society. Much of the distrust stems from the central role the military played in perpetuating a martial law regime that was dismantled in 1987.

There is also a widespread perception that decreasing tensions with China have destroyed the rationale for military service that once existed.