BEIJING, May 19, (AP) -- Chinese security forces wounded as many as 80 Tibetans in a clash over China's ban on photographs of the Dalai Lama, a Tibet monitoring group said Sunday.

Details of Tuesday's confrontation -- at least the second over the ban -- were sketchy, but witnesses reported seeing two trucks of badly beaten Tibetans, mainly monks and nuns, arriving at a hospital in Lhasa, the Tibetan capital, the Tibet Information Network said.

"Some people were walking. Some people could not walk. They were holding each other, and some were crying and screaming," the group quoted Takeo Fujimoto, a Japanese tourist, as saying.

"It was not like a car accident. Their whole faces were sore and covered with blood, and some people could not move."

A week earlier, monks at Ganden monastery, east of Lhasa, threw stones at an official ordering the removal of photographs of the Dalai Lama, and police shot at least three monks, the Tibet Information Network reported. China's army entered Tibet in 1950, and formally took over the region the following year, claiming it historically was Chinese territory. Since then, it has brutally suppressed demonstrations for Tibetan independence and tried to discredit the Dalai Lama -- Tibetan Buddhism's leader -- who went into exile in 1959.

Independence sentiment among Tibetan Buddhist clergy and fervently religious Tibetans remains strong.

In early April, Beijing banned displays of the Dalai Lama's photographs -- which are venerated by Tibetan Buddhists -- in monasteries and temples. Fujimoto spoke with the Tibet Information Network from a hotel in Katmandu, Nepal. China has barred all but a few Western reporters from traveling to Tibet since 1989.