Masked men attacked passengers after storming a train station in Hong Kong's Yuen Long district on Sunday.
Police say dozens of people are injured with one person in critical condition.
It comes after the latest pro-democracy rally in the centre of Hong Kong.
Demonstrations were also protesting against a controversial bill that allows extraditions to mainland China.
It's still unclear who the mob was or why the attacked the passengers.
Iran halting indirect talks with US over Israel's Lebanon incursion
Iran is halting indirect negotiations with the US after Israel ordered troops to push deeper into Lebanon to battle Tehran-backed Hezbollah, the Iranian news agency Tasnim said on Monday, complicating diplomatic efforts to end three months of war.
Trump says Iran really wants to make a deal with the US
President Donald Trump on Monday said that Iran really wanted to make a deal with the US and that it would be a good one for Washington and its allies.
Israel's Netanyahu orders attacks in Beirut's southern suburbs
Israeli Prime Minister Benjamin Netanyahu ordered attacks on the Hezbollah-controlled southern suburbs of Beirut on Monday, signalling further escalation of a war that has complicated mediation towards resolving the US-Iran conflict.
Malaysia bars under-16s from signing up for social media
Malaysia has begun barring those aged under 16 from registering accounts on social media platforms, its communications regulator said on Monday, as it boosts efforts to protect minors from exposure to harmful content online.
Kuwaiti forces deal with missile, drone attacks on Monday
Kuwait's Chief of the General Army Staff announced its air defence forces intercepted hostile missile and drone attacks early on Monday.
