A worker at the Tibetan Youth Travel Service confirmed the ban, which became effective on Tuesday, July 14, 2011, related to celebrations marking the 60th anniversary of Chinese rule in Tibet, which according to a report scheduled until July.
Meanwhile, the regional tourism bureau declined to comment when contacted by AFP, while a spokesman for the Tibetan government said he was not aware of the situation.
Tension in Tibet occurred when many of its citizens accused the government of trying to dilute their culture and call that their worries over what they perceive as the domination of the majority Han ethnic group.
Anxiety continues to be a big anti-government riots in Lhasa in March 2008, which later spread to neighboring provinces.
Immediately after the riots of 2008, foreign tourists are prohibited from visiting the Himalayan region for over 12 months.
In March this year, Tibet once again closed to foreigners before warning the riots. However, travel agencies said that foreign visitors can travel from April to June.
Even when foreigners are allowed entry, the government asked them to obtain special permission, other than Chinese visa, and travel in groups.
China, who said the standard of living in Tibet increased significantly since China ruled the region in 1951, has increased security in Tibet since riots in 2008. However, reports still emerge riot. An area in Sichuan province in southwest China hit by demonstrations earlier this year after a Tibetan monk sacrificed themselves and died in the incident which seemed to be the anti-government protests.