Against a backdrop of further violent protests, Hong Kong’s leader Carrie Lam has scrapped talks with US senator Ted Cruz after her office requested the meeting be kept completely confidential, the American politician has said.

Mr Cruz, the highest profile US politician to visit the city since anti-government protests broke out more than four months ago, said Ms Lam’s representatives had also requested that Mr Cruz refrain from speaking to the media about it, he told journalists on Saturday.

“She seems to misunderstand how free speech operates, and also how freedom of the press operates,” said Mr Cruz, a Republican senator from Texas and a vocal critic of China who was stopping in Hong Kong for two days as part of a regional tour.

“Ms Lam’s cancelling the meeting is not a sign of strength. It’s a sign of weakness. It’s a sign of fear of the protesters in the streets of Hong Kong.”

Responding to a request for details about the scheduled meeting, Ms Lam’s office said in an email to Reuters: “The chief executive did not meet with the said US senator”.

Protesters defied official warnings that they were gathering illegally and police said rioters had launched petrol bombs and damaged a subway station, AP reports.

The rallies in Kowloon and a small, peaceful gathering of retirees who shouted at plainclothes police officers outside police headquarters on Hong Kong Island maintained pressure on Ms Lam, to bend to the months-long protest movement’s demands ahead of her annual policy address on Wednesday.

Hong Kong has been paralysed by the unprecedented protests calling for democracy and against police brutality.

The former British colony was returned to China in 1997 and promised broad autonomy for 50 years under a “one country, two systems” model. But many in Hong Kong accuse Beijing of eroding its freedoms.

Mr Cruz said he stood in support of those protesting.

“I stand with the people of Hong Kong calling on the government of China to honour the promises it made to the world when it promised to maintain political freedom in Hong Kong,” said Mr Cruz, who wore black to show support for the black-clad protest movement.

Asked if he condemned violence that has flared during the protests, Mr Cruz said he advocated non-violent protest to the demonstrators and democracy activists he had met.

On Saturday many thousands of marchers joined the rally in Kowloon, classified by police as an illegal gathering.

Police wearing riot helmets and banging their plastic shields followed some distance behind, clearing road blocks left by the march.

There were gatherings of several hundred people in other locations, too. A rally in a shopping mall pulled together about 300 people who sang and put up protest posters.

The majority of protesters wore masks over their mouths in defiance of a week-old ban that makes face coverings punishable by one year in jail when worn at rallies.

The police force reported on its Facebook page that rioters tossed petrol bombs inside a Kowloon subway station, “posing a threat to the safety of citizens” but causing no injuries.

Overall, however, the protests were lower-key and appeared to lack the numbers of some much larger demonstrations seen during the more than four months of unrest that have gripped the semi-autonomous Chinese territory, according to AP.

As recently as last Sunday, tens of thousands of masked protesters had hit Hong Kong’s rain-drenched streets.

Agencies contributed to this report