Hong Kong's District Court sentenced media tycoon Jimmy Lai Chee-ying to 13 months in prison on Monday for inciting others to participate in an unauthorized assembly last year.

Lai was one of eight people sentenced on Monday for their roles at an unauthorized assembly in June last year in Causeway Bay on Hong Kong Island.

Judge Amanda Jane Woodcock ruled that deterrent sentences were necessary since the defendants ignored the serious risk of the COVID-19 pandemic to public health, and some committed the offenses while on bail.

Woodcock said the defendants "wrongly and arrogantly "thought that the assembly was more important than protecting public health, adding that they "belittled" a "genuine" public health crisis.

The pandemic posed a threat to public safety, which was an important consideration by the police in banning the assembly, Woodcock said, noting that since the beginning of last year, Hong Kong had experienced four waves of the pandemic.

She said there had also been a possible risk of violence during the assembly, given that social unrest had not entirely disappeared at that time.

The 13-month sentence will run concurrently with Lai's previous sentences. He is serving a 20-month sentence in Stanley Prison for participating in three illegal assemblies in 2019.

Seven other defendants were also sentenced to jail terms ranging from four months and two weeks to 14 months for taking part in the same assembly.

Activist Chow Hang-tung was sentenced to 12 months and Gwyneth Ho Kwai-lam to six months.

The court convicted Lai and Chow on Thursday for incitement by knowingly taking part in an unauthorized assembly at Victoria Park on June 4 last year, while Chow and Ho were also found guilty of knowingly participating in the same assembly.

Among the remaining five, who pleaded guilty on Nov 1, former lawmaker Lee Cheuk-yan was sentenced to 14 months, Richard Tsoi Yiu-cheong to 12 months, Leung Kam-wai and Leung Yiu-chung to nine months, and former Democratic Party chairman Wu Chi-wai to four and half months.

The case also involves another 18 people, including former lawmaker Albert Ho Chun-yan and activist Joshua Wong Chi-fung. Twenty-four people have been sentenced so far.

The remaining two defendants, Nathan Law Kwun-chung and Sunny Cheung Kwan-yang, fled the city before the trial. The court has issued arrest warrants for them.