Thursday marks a key - and painful - date for millions of practitioners of Falun Gong spirituality, 18 years after the Chinese government began a violent crackdown on devotees in China.

Thousands of people - even those who might not have been persecuted for their faith - marched in the streets of Taipei on Sunday protesting the treatment of Falun Gong practitioners in China.

Falun Gong blends tenets of Buddhism and Daoism as well as aspects of qigong exercises, and devotees are known for engaging in public meditation sessions.

Marchers wearing bright golden robes beat on drums as they walked through downtown Taipei, while others dressed in white carried photographs of Falun Gong followers who have died in China, an epa journalist reported.

Some at the Taipei demonstration also staged mock torture acts performed on Falun Gong prisoners, and a scene of Chinese doctors harvesting the organs of Falun Gong devotees.

Chinese tourists snapped cellphone photos of the demonstration, showing amusement and confusion at a demonstration that would rarely be allowed on the mainland, where authorities regard Falun Gong as an anti-government cult.

In Taiwan, where people enjoy freedom of religion, there are more than 500,000 people who read Falun Gong books, Flora Chin-hua Chang, a professor at National Taiwan University and a spokeswoman for Falun Gong on the island, told epa.

Chang said the Falun Gong movement, which started in Taiwan in 1994, holds three major demonstrations per year: one on Apr. 25 marking the 1999 peaceful picket in Beijing by thousands of devotees seeking government recognition of the group; one on May 13 for World Falun Gong Day; and one around Jul. 20 which mourns the 1999 crackdown and persecution of followers.

Despite the tensions between Taipei and the mainland, Chang said Beijing's opposition to Falun Gong has indirectly influenced authorities in Taiwan, and some public events where practitioners distributed Falun Gong literature have been shut down by the authorities.

Speaking at a press conference following the demonstration on Sunday, Chang urged everyone to stand together to stop the persecution of Falun Gong followers as soon as possible, adding that millions of practitioners have gone missing in China since 1999.

The report "Exposing China's Lucrative Organ Transplant Industry" published in 2016 by the NGO The International Coalition to End Organ Pillaging in China, alleges that starting in the year 2000, organ harvesting was used as a means of wiping out the Falun Gong movement.

The report claims that hundreds of hospitals and medical facilities in China have performed 1.5 million-2.5 million transplants over the last 16 years, mostly on Falun Gong prisoners.

Publicly founded in 1992 in northern China by Li Hongzhi, a follower of Buddhism and Daoism, Falun Gong had drawn millions of followers within a few years, and its popularity spread around the world.

Li claimed that through practicing Buddhist meditation and reading Buddhist literature, followers could improve their character and heal themselves.

But by 1996 Falun Gong had drawn the suspicion of the Chinese government, its books were banned and Li fled to the United States.

Large-scale arrests of Falun Gong devotees followed, culminating in the July 1999 crackdown that saw thousands more detained and tortured.

According to Amnesty International, the repression of the movement continues to this day.

A report issued by the NGO in February 2017 details the case of Falun Gong follower Chen Huixia, who has been detained for over a year and who faces the possibility of life imprisonment for "using an evil cult to undermine law enforcement," according to the indictment against her by the prosecutor in December 2016.