CAIRO  Ramadan Aboul Hassan left his house one night about three weeks ago to join a neighborhood watch group with two friends and did not return. The next time their relatives saw the three men they were emerging Wednesday night from a maximum security prison, 400 miles from home, run by Egypt’s military. Some family members said they bore signs of torture, though others denied it.

While many here have cheered the military for taking over after last week’s ouster of President Hosni Mubarak and for pledging to oversee a transition to democracy, human rights groups say that in the past three weeks the military has also played a documented role in dozens of disappearances and at least 12 cases of torture  trademark practices of the Mubarak government’s notorious security police that most here hoped would end with his exit.

Some, like Mr. Aboul Hassan and his two friends, were not released until several days after the revolution removed Mr. Mubarak.

Now human rights groups say the military’s continuing role in such abuses raises new questions about its ability to midwife Egyptian democracy.