A deepening sense of impasse gripped Hong Kong on Monday as pro-democracy protests entered their fourth week, with the government having limited options to end the crisis and demonstrators increasingly willing to confront police.

Dozens of people were injured in two nights of clashes over the weekend in the densely populated Mong Kok district of the Chinese-controlled city, including 22 police, media said. Four people were arrested on Sunday for assault, police said.