A Chinese court has sentenced 10 people who sought to flee Hong Kong by speedboat earlier this year to between seven months and three years in prison.

The Yantian District Court in the southern city of Shenzhen on Wednesday gave the harshest sentence to one of the two accused organizers of the ill-fated Aug. 23 attempt.

The defendants are believed to have feared they would be prosecuted for their activities in support of Hong Kong’s pro-democracy movement. Hong Kong media reports said at least one may have had a warrant out for his arrest under a tough new national security law imposed on the semi-autonomous territory by Beijing in June.