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

Chinese authorities have created a two-tier system, the report said, 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.

"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 report said.

Fewer than 10 percent of prefectures in China still use the older, slower system, with all but one inhabited mostly by ethnic minorities, according to the 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.

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."