Hong Kong police have arrested 11 people on suspicion of helping 12 pro-democracy activists who attempted to flee to Taiwan by speedboat last year.

News outlets in Hong Kong said eight men and three women between the ages of 18 and 72 were detained Thursday. Among those arrested were Daniel Wong, a well-known human rights lawyer and pro-democracy supporter. Wong posted on his Facebook page early Thursday morning that police had arrived at his apartment to arrest him.

The 12 activists were arrested in August by the Chinese coast guard while trying to escape to Taiwan. During a court hearing in the southern city of Shenzhen late last month, eight of them were sentenced to seven months in prison on a charge of illegally crossing a border, while two others were convicted of organizing an illegal border crossing and sentenced to two years and three years in prison.

Two juveniles who were also arrested on the ill-fated journey were sent back to Hong Kong after pleading guilty to illegal border crossing.

Many pro-democracy activists have fled to Taiwan, the self-ruled island claimed by China, out of fear they would be punished for their activities, especially under the harsh new national security law approved by the Chinese central government in June.

Thursday’s arrests come a week after more than 50 pro-democracy activists were arrested in the biggest crackdown under the new law, which was enacted in response to the massive and often violent pro-democracy demonstrations that engulfed the financial hub in the last half of 2019.

Under the new law, anyone in Hong Kong believed to be carrying out terrorism, separatism, subversion of state power or collusion with foreign forces could be tried and face life in prison if convicted.

Western governments and human rights advocates say the measure effectively ends the self-autonomy guaranteed under the pact that switched control of Hong Kong from Britain to China in 1997.