Two Chinese dissidents - one a student at Utah State University in Logan, Utah - were stopped in Tokyo from boarding a flight for Beijing Thursday because the Chinese government told airlines not to accept them, they said.

Wang Bingzhang and Tang Guangzhang, leaders of the Chinese Alliance of Democracy, said they were not allowed to get on Japan Airlines Flight 5.The men said they wanted to come to Beijing to "investigate" the student pro-democracy movement, the biggest ever in Communist China's 40-year history.

Wang, a native of China who has become an American citizen, said he had no visa to enter China. He said he had planned to stay in China for several days "on transit" and then head to Thailand.

Tang, a Chinese citizen and chemistry student at Utah State University, said he did not understand why he had been denied the right to board a plane to his homeland.

He was thrown out of China on Jan. 9 after he was apprehended in Shanghai with copies of China Spring. The magazine is published by the Chinese Alliance of Democracy, based in New York City. Wang set up the dissident group in 1983 to promote democracy in China.

Chinese officials have declared the alliance and its magazine illegal and reactionary.