HOLDING candles and wearing black, tens of thousands of people gathered in a park in Hong Kong on June 4th to mark the crushing of the Tiananmen Square protests 25 years ago. Elsewhere in China, and especially around Tiananmen, police tightened security and detained dissidents to prevent any attempt to commemorate the bloodshed. But despite their large-scale show of sympathy for China’s failed pro-democracy movement, activists in Hong Kong are bitterly divided and at odds with the government over how to achieve democracy in the territory itself. The coming year will see tempers flare.

Turnout at the annual observance in Hong Kong of the anniversary of the army action in Beijing on the night of June 3rd was one of the largest ever seen. Participants filled the six football pitches in Victoria Park. They sang pro-democracy songs and listened to local politicians calling on China to change its verdict on the Tiananmen unrest, which at the time the Communist Party called a “counter-revolutionary rebellion”. The party now tries to avoid all mention of the episode. Internet censors in China erased messages referring to it on Chinese social media. Police in Beijing summoned several foreign journalists and warned them to stay away from “sensitive” people and places during the anniversary. Not since the Arab spring of 2011, when Chinese officials feared that copycat demonstrations might occur in China, have police issued warnings to such a large number of reporters.

Hong Kong’s freedom to commemorate the Tiananmen unrest is a point of pride for many—the territory has retained many of its social and political freedoms, in spite of returning to Chinese rule in 1997. It is also a subject of curiosity among the many mainland Chinese who flock there for sightseeing and shopping. A few even join in. In April the organisers of the annual candlelit vigil opened what is billed as the world’s first Tiananmen museum: a tiny fifth-floor room in a backstreet building where visitors can see photographs of the protests in 1989 and watch video testimonies of parents of those who were killed. A 23-year-old visitor from China says she only learned about what really happened when she visited Germany three years ago and looked for videos of the upheaval on YouTube, which is blocked in China.

This year’s candlelit vigil was of special importance for members of Hong Kong’s pro-democracy camp. They are gearing up for what is likely to be an unusually troubled period in the territory’s politics, as it prepares for what China has promised will be the first election of Hong Kong’s chief executive by universal suffrage in 2017. Pro-democracy politicians hoped a big turnout would reflect support not only for democratic reform in China generally, but also specifically in Hong Kong. The rules for the elections in 2017 are likely to be finalised within a year or so. Many believe China wants them to be rigged to exclude pro-democracy candidates.

At the vigil in Victoria Park, one activist from mainland China urged the crowd to support a civil-disobedience movement called Occupy Central. It plans to hold a “referendum” on June 22nd to gauge public opinion on how the elections in 2017 should be conducted. Benny Tai, a law professor at Hong Kong University who is an organiser of Occupy Central, says he hopes that 300,000 people will cast votes at street stalls and online to show their preference among three possible methods for conducting the polls in 2017. All three, however, involve diluting the role of an official nominating committee in the selection of candidates. The central government in Beijing, and Hong Kong’s own government, have rejected this possibility. The nominating committee is seen by officials in Beijing as a crucial tool for excluding outspoken democrats.

The nuclear option

Occupy Central’s threat to block streets in Central, as Hong Kong’s main financial district is known, if their demands for free elections are not met has spooked officials in Hong Kong and Beijing. Mr Tai is non-committal about when his supporters might launch such action. It is possible, he says, that some radical students may try as early as July 1st, an official holiday and a traditional day of protest in Hong Kong. But he says he favours waiting until the government’s plans for the elections are clearer; possibly late this year or early next. An opinion poll published this month by academics at Hong Kong University found that about a quarter of respondents supported Occupy Central’s plans.

But pro-democracy politicians are themselves divided. Moderates complain about the movement’s tactics, such as only including proposals known to be unacceptable to the government in the vote on June 22nd. Some believe that compromise with China is necessary. Even Mr Tai speaks of civil disobedience as a “nuclear weapon” whose power consists in the threat of its use. “When you use it you destroy everything, including yourself,” he says. But radicals are getting impatient. Michael DeGolyer of Hong Kong Baptist University notes that in contrast to China, where people are much freer and far more prosperous than they were in 1989, Hong Kong’s citizens (though still much freer and on average richer than mainlanders) have experienced no such uplift. Protest in Hong Kong, compared with some other big cities in Asia, has long been remarkable for its orderliness. That might change.