HONG KONG: Hong Kong police arrested about 370 people Wednesday - including 10 under China's new national security law - as thousands defied a ban on protests on the anniversary of the city's handover to China.

Police used water cannon, pepper spray and tear gas in a series of confrontations with protesters, one day after China drew global criticism for imposing the controversial legislation on the financial hub. Beijing said the law would restore stability after nearly a year of unrest, but instead it sparked the worst street violence in months.

Police said seven officers were injured - one was stabbed in the shoulder as he tried to make an arrest, and three others were hit by a "rioter" on a motorcycle.

Under the new law, certain political views and symbols became illegal overnight - including showing support for Hong Kong, Taiwan, Xinjiang and Tibet independence. Details released by police Wednesday accused those arrested under the new legislation of possessing independence flags, stickers and flyers.

"Advocacy for independence of Hong Kong is against the law," security minister John Lee told reporters.