MOSCOW (AP) — An opposition group in Russia announced Thursday that it is shutting down after authorities listed the organization as “undesirable” as part of a multi-pronged crackdown on dissent.

The leader of Open Russia, Andrei Pivovarov, said the group funded by a self-exiled Russian tycoon was ceasing operation to protect its members from prosecution.

A 2015 Russian law made membership in “undesirable” organizations a criminal offense. The government has used the law to ban about 30 groups.

“It's awfully sad” to close Pivovarov tweeted, adding that “an increasing number of people in the country want changes” and “Russia will be free, and it will happen very soon.”

Open Russia was funded by tycoon Mikhail Khodorkovsky, who moved to London after spending 10 years in prison in Russia on charges widely seen as political revenge for challenging President Vladimir Putin’s rule.

In March, police briefly detained about 200 people participating in a Moscow forum Open Russia organized of independent members of municipal councils.

Pivovarov pointed to a bill making its way through the Russian parliament that would make membership in “undesirable” organizations punishable by prison terms.

An earlier law obliged non-governmental organizations that receive foreign funding and engage in activities loosely described as political to register as “foreign agents.”

Authorities have described the laws as a response to alleged Western efforts to undermine Russia, but critics describe them as part of the Kremlin’s efforts to stifle dissent.

The government has intensified its crackdown on the opposition as the country is preparing for a a September parliamentary election and the popularity of the main Kremlin-backed party, United Russia, has waned.

Opposition leader Alexei Navalny, Putin's most determined political foe, was sentenced to 2 1/2 years in prison in February after his return from Germany where he spent five months recuperating from nerve agent poisoning he blamed on the Kremlin. Russian officials have rejected the accusations.