HONG KONG, Oct 16 (Reuters) - Seven Hong Kong democracy campaigners, including former lawmakers, were sentenced on Saturday to up to 12 months in jail for their role in a protest last year against a sweeping national security law imposed by China. The seven had pleaded guilty to charges that included organising the unauthorised assembly on July 1, 2020, when thousands of protesters took to the streets. Police, who had banned the demonstration citinbg coronavirus restrictions, fired tear gas and water cannon to disperse them. The activists included Figo Chan, a former convenor of the now-disbanded Civil Human Rights Front (CHRF); Tsang Kin-shing and Tang Sai-lai of the League of Social Democrats; former district councillor Andy Chui; and former legislators Wu Chi-wai, Eddie Chu and Leung Kwok-hung. Chan was jailed for 12 months, while the others were given sentences from six to ten months. "The nature of incitement was serious," said the judge, Douglas Yau, noting that it created the risk of violence. Beijing imposed a national security law on June 30 last year as a response to widespread anti-government protests in 2019 that roiled the city. The law, drawn up by China, sets out to punish subversion, secession, terrorism and collusion with foreign forces. The protest took place the next day - the first full day under the new law, though civil society groups had held deminstrations on July 1 for years to champion various issues, including democratic rights. Hong Kong returned to Chinese rule in 1997 with the promise its wide-ranging freedoms and high degree of autonomy would be preserved. Beijing and Hong Kong authorities have repeatedly denied curbing human rights and freedoms. "We could only choose civil disobedience… a peaceful, rational and non-violent way to express our demand against the national security law," Figo Chan said in mitigation. "In order to uphold the belief of civil disobedience, I decided to plead guilty, admitting that I violated the "evil public order law"." At least 370 people were arrested that day for illegal assembly and other offences, with ten involving violations of the security law, according to police. Tong Ying-kit, the first person convicted under the national security law, was sentenced in July to nine years in prison for terrorist activities and inciting secession. He was accused of driving his motorcycle that day into riot police while carrying a flag with the now-banned protest slogan "Liberate Hong Kong. Revolution of our times". According to the Security Bureau, more than 150 people have been arrested under the national security law. Among them, 100 people have been formally charged.