TAIPEI (Taiwan News) – Hong Kong streets were scarred by petrol bombs, tear gas and water cannon with blue dye at an illegal march in Tsim Sha Tsui by pro-democracy Hongkongers on Sunday (Oct. 20) as the city marked its 20th weekend of protests.

Authorities had forbidden the rally, but tens of thousands of protesters dressed in black nevertheless joined the anti-government demonstration. After two weeks of relative calm, the protest began peacefully in a familiar pattern, but soon descended into chaos as small groups of hardcore protesters began to hurl petrol bombs at the police, subway entrances and pro-Beijing businesses.

Police responded with jets of blue-dyed water and tear gas to disperse the protesters. Many who were hit with the water began to cough and vomit, suggesting an irritant possibly mixed in the water, reported Epoch Times.

A remote-controlled bomb disposal robot was also seen navigating towards a cardboard box placed on the street with wires sticking out of it. A loud bang was heard after the police detonated the box, but it was unclear what was inside it, reported Liberty Times.

A sensitive incident also occurred as the police sprayed blue-dyed water cannon at Kowloon Mosque, the city's largest mosque, which angered the Muslim community. In a statement posted by the Muslim Council of Hong Kong, said it will not seek revenge but urged both the Hong Kong police and protesters to "seek unity over division," according to BBC.

Earlier this month, Hong Kong leader Carrie Lam invoked a colonial-era emergency law to ban wearing masks at protests, causing new waves of protests. On Wednesday (Oct. 16), Hong Kong activist Jimmy Sham was attacked with wielding hammers and wrenches, which has also contributed to the escalation of clashes in recent demonstrations.

Protesters set fire at subway entrance. (CNA photo)