It is understood that national security police arrested 11 people on Thursday morning, with local media reporting that the arrests are related to the 12 Hongkongers who left Hong Kong by boat in August.
Democratic Party district councillor and lawyer, Wong Kwok-tung, wrote on social media that police turned up at his home at around 6am.
Pro-democracy campaigner, Willis Ho, also wrote on her social media that her mother had been taken away.
The eight men and three women arrested are aged between 18 and 72 years.
It follows the arrests last week of more than 50 pan-democrats linked to primary votes for Legco elections last year.
Local media reported that Hong Kong police had arrested 11 individuals for suspected crimes related to assisting a group of 12 individuals who attempted to escape the city. The 12, who were arrested by the Guangdong coast guard, had been facing protest-related charges in Hong Kong.
Last month, 10 of them were jailed in Shenzhen for up to three years. The remaining two, who were minors, were sent back to Hong Kong. (Additional reporting from Reuters)