As thousands of people attended New Year’s anti-government march in Hong Kong, the city’s police arrested about 400 people on charges of illegal assembly and possession of arms.

Demonstrators came out en masse on Wednesday for the march organizers had to eventually cancel following police orders, that later led to clashes between officers and the more radical protesters.

Although permission for the demonstration had been granted, police urged organizers – the Civil Human Rights Front – to end the procession three hours after it started, arguing some protesters had begun throwing stones and Molotov cocktails and burning shops and banks.

The trouble started after an activist vandalized a branch of banking giant HSBC, which led to police cracking down on them with teargas, according to local media.

On Tuesday, the city’s embattled leader Carrie Lam said in a New Year’s Eve that she had the responsibility to solve the city’s problems, which has been rocked by anti-government protests for more than six months.

Lam expressed hope for reconciliation in 2020 and said Hong Kong people have “resolved many difficulties before.”

Demonstrations in Hong Kong began in June following a controversial extradition bill, already withdrawn by the government, but have mutated into a movement seeking to improve Hong Kong’s democratic mechanisms and safeguard the region’s partial autonomy from Beijing.

Months of protests have plunged Hong Kong’s economy into recession for the first time in a decade, having contracted by 2.9 per cent in the third quarter, due to falling imports and exports, retail sales and declining tourism.

The protests have been largely peaceful for much of December after pro-democracy candidates overwhelmingly won district council elections the month before.

Hong Kong’s protests are largely leaderless and organised online. They were initially sparked by a now-abandoned attempt to allow extraditions to the mainland but have since morphed into a popular revolt against Beijing’s rule.

The controversial China extradition bill was withdrawn in early September but the movement has morphed into a wider campaign for greater democracy and against alleged police brutality.