Hong Kong struggled to recover Monday, with the metro only partially functioning and infrastructure extensively damaged, after scores of protesters were arrested in violent clashes overnight that drew the first warning from the Chinese military.

Tens of thousands of protesters marched peacefully through the center of the Chinese-ruled city Sunday, wearing face masks in defiance of colonial-era emergency powers that threaten them with a maximum of one year in prison for hiding their faces.

However, the rallies deteriorated into running clashes as night fell. Police fired tear gas and used baton charges in an attempt to disperse petrol bomb-throwing protesters in several locations across the Asian financial hub.