HONG KONG (Reuters) - Hong Kong police fired tear gas on Saturday night in confrontations with black-clad activists in the city’s Kowloon area, as the Chinese-controlled territory was again rocked by anti-government protests. Police kept out of sight during an afternoon that saw tens of thousands of protesters march through what is ordinarily a busy shopping district, but charged onto the streets after 9 p.m. (1300 GMT), with hundreds of officers in riot gear pushing crowds back.