One freed monk, who did not want his name revealed, said some had been beaten when they refused to answer questions about their identity, birthplace, parents and involvement in the protests, the biggest challenge to the junta in nearly 20 years.
"The food and living conditions were horrible," the monk, from Yangon's Pyinya Yamika Maha (A) monastery told Reuters.
Among those detained in the middle of the night on Wednesday was a Myanmar U.N. staff member and her two relatives. They were released, along with her driver, on Thursday, a U.N. source said.
PROTESTS IN INDIA
The crackdown has provoked protests around the world and on Thursday hundreds of Buddhist monks in yellow robes marched in India chanting hymns, and waving placards that read "Stop Killing" and "No violence against democracy".
Dozens of monks from Myanmar, living in the eastern Indian state of Bihar, joined the rally in the holy town of Bodh Gaya, the last resting place of Lord Buddha.
"The Buddhist community is shocked at the way the military rulers fired bullets on monks who were protesting peacefully," said Bhikkhu Bodhipala, chief priest of the Mahabodhi temple in Bodh Gaya.
Gambari was to brief Ban after arriving in New York on Thursday in the midst of international outrage at the use of soldiers against peaceful columns of Buddhist monks and civilians demanding an end to military rule.
Official media say 10 people were killed, including a Japanese video journalist, although Western governments say the final toll is likely to be far higher.
The body of 50-year-old Kenji Nagai, shot dead near Yangon's Sule Pagoda, returned home on Thursday for an autopsy whose results could lead to Tokyo making good on a threat to scale back economic assistance to Myanmar, one of Asia's poorest countries.
Fears of a repeat of 1988, when the army killed an estimated 3,000 people in a crackdown lasting several months, were not realised, but even China, the junta's closest ally, made a rare public call for restraint. China praised Gambari's mission -- which Western diplomats said Beijing helped facilitate -- saying it gave his efforts a "positive appraisal".
