May 26, 2008 (AFP)‚ A fire destroyed the top floor of a building at the Burmese embassy in Thailand on Monday, raising concern among aid groups that visas to get into the country for cyclone relief could be delayed.

Police said the visa section itself had not been touched by the early morning blaze, which a fireman on the scene said had begun in a room full of documents at the site on a busy thoroughfare in the Thai capital.

Burma’s ruling generals have been heavily criticised for delaying access of foreign aid workers to the secretive country to help with the relief effort after Cyclone Nargis, which left almost 134,000 people dead or missing.

The fire occurred just one day after an international conference in Burma, where UN secretary general Ban Ki-moon confirmed that the country’s secretive ruling junta had agreed to let in all foreign aid workers.

"We are ready to help the Myanmar embassy find out what caused the fire. But the embassy informed us that they will investigate themselves," said police investigator Lieutenant Tanapat Seehawong.

Western aid groups waiting for visas to enter Burma said they now feared more delays.

"We went this morning to check on our visa applications, and we were dismayed to see the place drenched after it had gone up in flames," said Melissa Winkler of the International Rescue Committee.

"This will clearly lead to more delays, and more delays in getting assistance to people in need," she said. "We were optimistic we would see processed visas first thing this morning."

Dozens of aid workers have been blocked from getting into Burma, which has long turned its back on the outside world. It has insisted on largely managing the relief work itself and all but closed the disaster zone to outsiders.