Protesters in Hong Kong are furious after police failed to stop an attack on them at a train station in Yuen Long on Sunday.
Dozens of men in masks attacked people, including many anti-government protesters, with wooden and metal sticks.
Some 45 people were injured and police had failed to make any arrests by Monday morning.
Police commissioner Lo said protests were behind the lack of police response because it meant “our manpower is stretched”.
Protesters suspect the attacks were an attempt to undermine their movement.
Hong Kong’s leader, Carrie Lam, condemned the attacks—but first condemned protests that took place earlier on Sunday.
Hundreds of thousands of marchers demanded a complete withdrawal of the extradition bill, which would allow extraditions to mainland China.
They also called for independent inquiries into the police use of force against demonstrations and the unconditional release of all arrested prisoners.
Later police attacked protesters occupying a road in Sheung Wan with rubber bullets and tear gas.