Human Rights Watch Tuesday urged Hong Kong to probe alleged police abuses at a massive anti-government rally this month, and claimed the police had used \"disproportionate force\" against the media. Tens of thousands of people took to the streets on July 1 to vent their frustration at government policies and soaring property prices in Hong Kong\'s biggest rally in seven years. The rally was largely peaceful but rights groups have accused police of violating the right to assembly after they arrested 231 people and used pepper spray to disperse a crowd after the march. The New York-based rights group said in a statement that some journalists had been hit with pepper spray directly in their face and eyes, and slammed the police for detaining a human rights observer who was videotaping the police action. \"If (Chief Executive) Donald Tsang and the Hong Kong government turn a blind eye to alleged police abuses, they risk Hong Kong\'s reputation as a bastion for civil liberties,\" said Sophie Richardson, HRW\'s Asia advocacy director. \"At a time when freedom of speech and assembly and the rights of a free press are under serious attack by Chinese security forces just over the border, it\'s essential for the Hong Kong government to demonstrate a strong commitment to the defence of those same rights and freedoms in Hong Kong,\" she added. Television news footage has showed police used pepper spray to disperse the demonstrators following a standoff which lasted a few hours. Some were later forcibly removed, handcuffed and carried into police trucks. Police and Security Bureau officials did not immediately respond to AFP\'s requests for comment. The police have reportedly defended their action, saying officers had acted in a restrained manner and used minimal force. The former British colony returned to Chinese rule in 1997 but retains a semi-autonomous status under the \"one country, two systems\" model, with civil liberties including freedom of speech not enjoyed in mainland China. Rights groups have expressed concern over the city\'s lower tolerance towards dissent in recent years, including the denial of entry to high-profile critics of China such as 1989 Tiananmen Square student protest leader Wang Dan.