With May's constitutional referendum fast approaching, the Burmese government is apparently tightening control over the issuance of tourist visas to the country.

A vast majority of tourists to Burma enter via flight from Thailand, having secured a Burmese tourist visa from one of Bangkok's multitude of travel agencies. But the Burmese Embassy in Bangkok is now rejecting some passports unless the owner of the passport appears in person at the embassy.

Specifically targeted by Burmese authorities are reportedly citizens of the United States, United Kingdom and Japan.

According to a Chiang Mai-based travel agent, Burmese Embassy staff are now requesting to speak in person with those wishing to enter the country, requiring additional verification as to the identity of some applicants as well as further details of the applicant's profession.

Asked whether it was now mandatory for persons from the U.S., U.K. and Japan to apply in person at the Embassy, a Bangkok travel agency confirmed that it was increasingly becoming the case. "We can still try to obtain the visa for them, but we cannot promise anything," stated an employee of Olavi Tours.

Remarking that the new obstacles for hopeful travelers to Burma are a relatively new phenomenon, the agents expressed their belief that the restrictions will be lifted in some four to five months.

Though the exact impetus for the actions of the Consular Services section of the Embassy are not known for sure, the steps are assumed to be related to the junta's desire to keep foreign reporters and journalists out of the country ahead of and during May's scheduled constitutional referendum.

The junta accused foreigners of entering the country under the guise of tourism to report on and cover last year's Saffron Revolution, which culminated in the deaths of dozens of protesters at the hands of security forces.

Kenji Nagai, the Japanese journalist shot dead at point blank range on September 27, had entered the country on a tourist visa.

The loosening of visa restrictions in five months time, if proven correct, would coincide with the start of high season for tourism in the Southeast Asian country, an industry that was devastated by events in the latter months of last year and has yet to fully recover.

Burmese Embassy staff in Bangkok were unavailable for comment.