Chinese courts have sentenced two leading figures in China's first opposition party to lengthy jail terms and given a four-year sentence to a leader of the banned Falun Gong spiritual movement as the government continued its crackdown on a wide range of dissent.

A Hong Kong-based human rights organization reported today that Tong Shidong, 65, an assistant physics professor at Hunan University, and Liao Shihua, a factory worker and labor organizer in the Hunan provincial capital, Changsha, were convicted of attempting to subvert state authority. The Information Center of Human Rights and Democratic Movement in China said Tong was sentenced to 10 years and Liao to six years.

At least 20 people, including veteran dissident Xu Wenli, have been sentenced to jail terms during the government's 13-month suppression of the first attempt to form an opposition party in Communist China. Xu's prison sentence of 13 years is the longest meted out thus far.

Meanwhile, the Information Center said that Li Fujun, a 37-year-old assistant professor at the Xinxiang Medical College in Henan province, was convicted of crimes relating to the Falun Gong movement and given a four-year prison term. The center said Li was convicted Thursday of organizing a protest in Beijing's Tiananmen Square and defending the group's claim that people can cure themselves without the aid of doctors or medicine. Thousands of Falun Gong practitioners have flocked to Beijing and hundreds have demonstrated in Tiananmen Square since China banned the popular group in July.

The center said that since New Year's Day, more than 100 Falun Gong followers have been detained in Beijing as they performed unprecedented acts of civil disobedience in defiance of the ban.

The crackdown on Falun Gong has dwarfed every campaign against dissent in China in the last 10 years except for the bloody suppression of student-led democracy demonstrations around Tiananmen Square in 1989. The Hong Kong rights group has estimated that China has sent as many as 5,000 Falun Gong adherents to labor camps. Last month, it jailed four leaders for up to 18 years after a court found them guilty of manslaughter and stealing state secrets. In November, four other leaders were sentenced to up to 12 years in prison in the southern island province of Hainan.

Falun Gong founder Li Hongzhi, who lives in self-imposed exile in the United States, has denied that his organization has any political agenda. The Communist government, on the other hand, calls Falun Gong an evil cult, bent on destroying Chinese society.