Calvin So, a victim of Sunday's Yuen Long attacks, shows his wounds at a hospital, in Hong Kong, China, July 22, 2019.
Calvin So, a victim of Sunday's Yuen Long attacks, shows his wounds at a hospital, in Hong Kong, China, July 22, 2019.

US President Donald Trump on Monday praised Beijing's handling of pro-democracy protests in Hong Kong, a day after suspected triad gangsters attacked demonstrators in a bloody escalation.

Hong Kong has been plunged into its worst crisis in recent history by weeks of marches, which drew millions, and sporadic violent confrontations between police and pockets of hardcore protesters.

The demonstrations have evolved into a call for democratic reforms, universal suffrage and a halt to sliding freedoms which China had promised to respect in the semi-autonomous territory after its handover from Britain in 1997.

"I know that's a very important situation for President Xi" Jinping of China, Trump said during a White House meeting with Pakistan's Prime Minister Imran Khan.

When a reporter suggested that the Hong Kong and Chinese governments were ignoring violence against the protesters, Trump replied that "I think it's been relatively nonviolent."

Hospital authorities said 45 people were wounded in the attack late Sunday which led to the arrest of six men, some of whom police alleged had triad gangster backgrounds.

"China could stop them if they wanted," Trump said of the protests.

"I'm not involved in it very much but I think President Xi of China has acted responsibly, very responsibly," said Trump, who last year began a trade war with China that has led to tariffs on hundreds of billions of dollars in mutual trade, a dispute still unsettled.

After Sunday's violence critics accused Hong Kong police of responding too slowly.

"They've been out there protesting for a long time. I've never seen protests like it where you have that many people. It looks like two million people," Trump said.

"Those are big protests. ... I hope that President Xi will do the right thing, but it has been going on a long time, there's no question."

Hardcore protesters have stormed Hong Kong's legislature, and on Sunday some demonstrators targeted with eggs and graffiti China's representative office in the financial hub, which China's foreign ministry called "absolutely intolerable."