FILE PHOTO: U.N. High Commissioner for Human Rights Michelle Bachelet holds a news conference at Centro Cultural Espana in downtown Mexico City, Mexico April 9, 2019 REUTERS/Carlos Jasso

GENEVA (Reuters) - The United Nations High Commissioner for Human Rights urged Hong Kong on Tuesday to exercise restraint and investigate evidence of its forces firing tear gas at protesters in ways banned under international law.

Hong Kong authorities should engage in meaningful dialogue with protesters to restore public security, Michelle Bachelet said in a statement, while welcoming chief executive Carrie Lam’s remarks on her commitment to listen to grievances.

“Officials can be seen firing tear gas canisters into crowded, enclosed areas and directly at individual protesters on multiple occasions, creating a considerable risk of death or serious injury,” Bachelet said.

Her office “urges the Hong Kong authorities to act with restraint, to ensure that the rights of those who are expressing their views peacefully are respected and protected, while ensuring that the response by law enforcement officials to any violence that may take place is proportionate,” she said.

Her spokesman Rupert Colville conceded that security forces in the former British colony were sometimes in a difficult situation. “We are not saying it is easy, but nevertheless they have to avoid excesses, otherwise they can just make the situation worse,” he said.

A state of “panic and chaos” exists in Hong Kong, Lam, the city’s embattled leader, said on Tuesday, defying calls to quit as the stock market tumbled, airlines flagged flight disruptions and anti-government protesters filled the airport.

Colville said Bachelet’s office was in contact with both Hong Kong and Chinese officials about the situation.

Asked about China’s comments that “sprouts of terrorism” were emerging in Hong Kong, he said: “The use of strong rhetoric of the type you mentioned can only serve to inflame tensions and make an extremely volatile situation worse. There needs to be a genuine attempt by all sides towards a process of dialogue.”