HONG KONG (AP) ― Authorities in mainland China and Hong Kong have arrested nine suspects in an attack on a former Hong Kong newspaper editor whose dismissal sparked protests over press freedom, police said Wednesday.

Kevin Lau was critically wounded Feb. 26 when he was attacked by a man with a meat cleaver who fled on a motorcycle driven by another man, police say.

The two suspected assailants were arrested in Guangdong, a province in mainland China that borders Hong Kong, and were both 37-year-old Hong Kong residents believed to have a background with Chinese criminal gangs, Hong Kong police commissioner Tsang Wai-hung told a news conference.

Chinese authorities informed Hong Kong police on Sunday that the two suspects, whom investigators in Hong Kong had identified, were arrested in Dongguan city in Guangdong. Guangdong police had no immediate comment.

Tsang said seven suspected accomplices in the attack were arrested Wednesday in Hong Kong. He said the investigation was ongoing.

Lau, a former editor for the respected Ming Pao newspaper, remains in a hospital.

His abrupt dismissal in January raised fears among journalists that the paper’s owners were moving to curb aggressive reporting on human rights and corruption in China.