Beijing effectively bans Tibetans and other ethnic minorities from obtaining passports, rights groups said Monday, amid a surge in Chinese tourists travelling abroad.

Chinese authorities have created a two-tier system -- one for areas populated by the country's ethnic Han majority and another, more cumbersome system for areas inhabited by the country's Tibetan and Muslim minorities, according to reports by Human Rights Watch (HRW) and the International Campaign for Tibet (ICT).

"If you are a religious minority who lives in a part of the country where most people are minorities, it's virtually impossible to get a passport," Sophie Richardson, China director at Human Rights Watch, told AFP.

In most parts of China, a passport must be issued within 15 days, and if there is a delay the authorities must notify the applicant.

But in Tibet and Xinjiang, inhabited by 10 million Uighurs, a Turkic-speaking Muslim minority, officials use an older method for passport applications that requires more documents and sometimes political vetting, the HRW report said.

Around one in 10 prefectures in China still use the older, slower system, with all but one inhabited mostly by ethnic minorities, according to the HRW report.

Only two passports were issued in Tibet's Changdu prefecture, known as Chamdo in Tibetan, in 2012, according to the report, even though it has a population of 650,000 people. No figures were available for Tibet overall.

Many Tibetan have complained about what they see as an unofficial method to deny them passports.

"There is no formal document stating that this is central policy," said one Tibetan who was not named, according to the ICT report. "But it seems that the authorities want to prevent the Dalai Lama's influence on Tibetans by stopping them from travelling to his teachings outside."

Others who have satisfied the requirements are still not issued travel documents.

"My passport application was refused just today; I have been working for several years in a foreign company and completely met the requirements but it still wasn't issued," said another Tibetan quoted in the ICT report.

"This policy will only deliberately and slowly alienate Tibetans."

China's foreign ministry referred inquiries by AFP to the public security ministry, which did not immediately respond to a request for comment.

Hundreds of Uighurs were detained last year for illegally entering Thailand, fleeing what rights groups say is religious persecution in China. The Uighurs claimed to be Turkish citizens and 181 have been allowed to go to Turkey with more than 100 others sent back to China.

Meanwhile, mainland Chinese travellers took more than 100 million "outbound" trips last year, according to government figures, although most visited Hong Kong, Macau and Taiwan.

"It's clearly not the case that the state is having massive difficulties issuing passports to some people," Richardson said. "You would think that capacity would be spread evenly across ethnic groups but that doesn't seem to be the case."