Myanmar's junta attacked "unscrupulous" citizens and foreign media on Friday for presenting a false picture of the devastation left by Cyclone Nargis as experts began mapping the extent of the disaster.

The New Light of Myanmar, the mouthpiece of the ruling generals, said people had been selling video footage "of invented stories" to foreign news organisations which tarnished the country's image.

"The people who are in touch with the situation feel that the despicable and inhumane acts by local and foreign anti-government groups and self-centred persons and their exploiting of the storm victims are absolutely obnoxious," the newspaper said.

Bootleg copies of DVDs showing the devastation in the hardest-hit Irrawaddy delta have been snapped up on the streets of the former capital Yangon and smuggled out of the country.

Police detained famous activist/comedian Zarganar on Wednesday night and seized his computer, several banned films and records of the cyclone damage.

Newspaper, television and radio are tightly controlled by the military government, which also severely restricts international media access to the former Burma.

The New Light of Myanmar accused foreign media of running "groundless news stories with the intention of tarnishing the image of Myanmar and misleading the international community into believing that cyclone victims do not receive any assistance."

The first major criticism of foreign media coverage of the disaster followed a recent report on a satellite television network of bootleg video footage being sold at a Yangon market.

On Friday, police swooped on satellite television suppliers in Yangon, ordering them not to sell or install new receiver dishes.

Many such dishes, which provided one of the few conduits into the isolated country, were destroyed in the cyclone.

"Thanks to a tip-off given by an official, we were able to hide the things we had on sale," said one dealer.

In January, the government hiked the annual licence fee from around $6 to $909 (3 pounds to 463.50 pounds) in an apparent bid to curtail satellite access.

RIGHTS PROBE DEMANDED

In Geneva, the United Nations human rights expert for Myanmar urged the junta to investigate reports its soldiers shot dead at least 36 prison inmates during unrest in the country's most infamous prison at the height of the May 2 storm.

Tomas Ojea Quintana, who reports to the U.N. Human Rights Council, also called for the free flow of aid to the delta.

Dozens of delta villages, some visited by Reuters, have yet to receive any relief assistance since the May 2 cyclone swept over the area and Yangon, leaving 134,000 dead or missing and 2.4 million people in desperate need of help.

The newspaper report accused media organisations and local people of "luring naive storm victims" with leading questions on their living conditions a week after the junta began evicting thousands of people from state-run camps out of apparent fear the tented villages could become permanent.

A team of 200 international disaster and aid experts fanned out across the delta to assess the extent of the cyclone destruction and gauge whether farmers would be able to plant crucial monsoon rice crops by the end of July.

"They have begun looking at areas today and will report back in the middle of next month," a spokeswoman for the ASEAN-UN "Emergency Rapid Assessment Team" told Reuters.

Plans to accelerate the delivery of aid to the delta were delayed on Friday when poor weather grounded seven U.N. World Food Programme helicopters in neighbouring Thailand.

The helicopters, part of a fleet of 10 approved by the junta two weeks ago, are urgently needed by relief workers, but only one has so far arrived in Yangon.

A top U.S. military commander said on Friday the United States continued to extend its offer to help with the delivery of aid to the delta, but the regime had not replied so far.

Lt. Gen. John Goodman, commander of the joint task force Caring Response, said 22 heavy-lift helicopters were on standby in Thailand if Myanmar's generals gave the green light.

"We offered them to ride on our helicopters, to prescribe routes. I did everything that I thought was diplomatically and logically feasible to find a way for them to say yes," he told Reuters after his talks with a Myanmar general on Monday.