YANGON, Myanmar - Myanmar's military junta has detained a popular comedian who had just returned from an aid trip to the cyclone-ravaged delta, a region where a human-rights group said yesterday that the regime was forcing survivors to do menial labor for food.

Maung Thura - whose stage name is Zarganar - was taken from his home in Yangon by police after going to the Irrawaddy Delta to donate relief items to survivors, his family said.

In a report, Amnesty International cited several cases of forced labor in exchange for food in the delta, and accused the regime of stepping up a campaign to evict the homeless from shelters.

The London-based group also said authorities in several cyclone-hit areas continue to divert aid despite the junta's pledge to crack down on the practice.

"Unless human rights safeguards are observed, tens of thousands of people remain at risk," Amnesty said in its report. "Respect for human rights must be at the center of the relief effort."

More than a month after the storm, many people in stricken areas still have not received any aid, and the military regime continues to impose constraints on international rescue efforts, human-rights groups say.

U.S. Navy ships laden with relief supplies steamed away from Myanmar's coast yesterday, their helicopters barred by the junta even though millions of cyclone survivors need food, shelter or medical care.

Zarganar, 46, who works as a dentist to pay the bills and is known both for his antigovernment barbs and his work for cyclone victims, was taken into custody Wednesday night after police searched his house.

An Amnesty representative said Zarganar's detention was indicative of the kinds of human-rights concerns that the group was trying to highlight.

"There's simply no doubt this was done for political reasons . . . but has an extra element because it can be presumed to be linked to the humanitarian assistance effort," Amnesty researcher Benjamin Zawacki said.

The government says Cyclone Nargis, which struck Myanmar on May 2-3, killed 78,000 and left an additional 56,000 missing. The United Nations says more than one million still desperately need food, shelter or medical care.

This week, Zarganar gave interviews to several overseas media outlets, including the BBC, that were critical of the government relief effort.

The junta is sensitive to being embarrassed abroad, and has a record of persecuting people who give interviews to foreign media.