Rights protesters, China supporters greet President Xi in Seattle

SEATTLE (Reuters) - About 100 people protesting against human rights abuses in China greeted President Xi Jinping in Seattle on Tuesday, in what is likely to be the first of a series of demonstrations against China's leader during his week-long U.S. visit.

In downtown Seattle, a crowd supporting Falun Gong, a religious group that says it is repressed in China, waved signs against what it called China's theft of prisoners' organs.

"Falun Gong practitioners have been put into forced labor camps, prisons, and mental hospitals, and they have been killed for their organs," said Michael Green, 38, of Seattle.

At the same time, a group of pro-Chinese protesters, some of them wearing hats emblazoned with "USA," waved Chinese and U.S. flags and large red cloth signs that read "Hello President Xi" in Chinese characters.

At one point, Xi's supporters attempted to drape a giant flag over a Falun Gong banner that read: "Forced organ harvesting of Falun Gong practitioners is not tolerated by heavenly principles."

There were no arrests by late Tuesday during what police said were peaceful demonstrations.

China's official atheist Communist Party does not tolerate challenges to its rule and religious activities must be state sanctioned.

In 1999, China's then-President Jiang Zemin launched a campaign to crush Falun Gong after thousands of practitioners staged a peaceful sit-in outside the leadership compound in Beijing to demand official recognition of their movement.

In Seattle, pro-Tibetan groups joined the protests against China's fight against separatism in the mountainous region, as did activists calling for China to curb militarization of the South China Sea.

Earlier this month, Yu Zhengsheng, a high-ranking member of the ruling Communist Party also in charge of religious groups and ethnic minorities, stressed China's official line that the Dalai Lama, a spiritual leader who fled China in 1959 after an abortive uprising against Chinese rule, is a violent separatist.

Xi is also likely to encounter protests on Wednesday when he tours Boeing Co's widebody plant in Everett, north of Seattle, nearby Microsoft Corp, and a high school in Tacoma.

"We hope that the CEOs of big companies like Microsoft, Apple and others including Google won't compromise with the Chinese because that would hurt the development of democracy," 60-year-old protestor Jin Xiuhong told Reuters.

(Reporting by David Ryder and Eric M. Johnson in Seattle; Additional reporting by Jane Lee in Seattle; Editing by Bill Rigby and Miral Fahmy)