China yesterday called pro-democracy demonstrations in Hong Kong "illegal", as state media insisted Beijing would not give in but would wait for public opinion to turn against the protests.

Chinese foreign ministry spokesman Hua Chunying said that "an illegal assembly" was held in Hong Kong on Sunday, followed by "a series of illegal activities".

"We fully believe in and support the Hong Kong SAR government to deal with this issue," she added.

China's Communist Party leader Xi Jinping has remained silent as he and other top party officials offered flower baskets in Tiananmen Square on Martyrs' Day, a new holiday to celebrate China's national heroes, AFP reported.

The previous evening, Mr Xi "appreciated a music concert", the party's official People's Daily newspaper reported. He was flanked by Premier Li Keqiang and former president Jiang Zemin, who rose to power following a violent military suppression of 1989 pro-democracy protests in Beijing.

China under Mr Xi has cracked down on dissent, but Hong Kong's leadership has denied speculation that Beijing would send in the army to quash the protests.

The People's Daily said on its website that the protesters were an "extreme minority" who have "destroyed the rule of law" in the city.

"This breach of the peace and extreme behaviour will ultimately lead to a breakdown in social order."

The China Daily said the protests were "taking a toll on local harmony and stability". The Global Times said the "tide will turn against the oppositionists" if Beijing stands firm.

"The central government will not step back just because of the chaos created by the oppositionists," it said.

Britain has voiced concern about the escalating protests in Hong Kong and called for "constructive" talks, while the US asked Hong Kong's leaders to show restraint.