HONG KONG (AP) — Four of 47 pro-democracy activists charged under Hong Kong's tough national security law were released on bail Friday after prosecutors dropped an appeal of an earlier court decision.

The 47 activists were charged Sunday with conspiracy to commit subversion under the security law over their involvement in an unofficial primary election last year, which authorities say was a plot to subvert state power and paralyze the government.

The four activists — Clarisse Yeung, Lawrence Lau, Hendrick Lui and Mike Lam — appeared in court on Friday prior to being released.

The four are among 15 activists who were granted bail by the court on Thursday after a four-day marathon hearing. Thirty-one defendants were denied bail, and Benny Tai, co-founder of the 2014 Occupy Central opposition movement, withdrew his bail application after he was remanded in custody in a separate case.

However, the Department of Justice appealed the decision to grant bail and all 47 activists remained in custody. Prosecutors dropped their appeal for the four released activists on Friday. The other 11 are to appear in court on Saturday.

The bail conditions for the four activists include surrendering their travel documents and abiding by a curfew. They also are not allowed to contact foreign officials or take part in elections.

The next hearing in the case is May 31.

Under Hong Kong’s common law system, defendants are usually granted bail for non-violent crimes. But the national security law removed the presumption of bail, with a clause saying it will not be granted unless the judge has sufficient grounds to believe defendants “will not continue to commit acts endangering national security.”

The 47 are part of a broader group of 55 activists who were arrested in January in connection with the primary election. Eight were not charged.

The primary was aimed at determining candidates for a Legislative Council election who would give the pro-democracy camp the best chance of gaining a legislative majority. The government later postponed the election, citing public health risks from the coronavirus.

If the pro-democracy camp had won a majority, at least some members of the camp had plans to vote down major bills with the intent of eventually forcing Hong Kong leader Carrie Lam to resign. Authorities said the activists’ participation in the primary was part of a plan to paralyze the city’s legislature and subvert state power.

The national security law criminalizes secession, subversion, collusion with foreign forces to intervene in the city’s affairs as well as terrorism. Serious offenders could face life imprisonment.