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.
Saudi-owned vessel targeted in Red Sea, crew safe, state news agency says
Saudi Arabian state news agency on Thursday confirmed that tanker Encelia was ablaze after an assault while sailing in the Red Sea.
US House passes $1 trillion defence bill despite Iran, Israel concerns
The US House of Representatives narrowly passed its version of a massive defence policy bill, despite Democrats' concerns about its huge price tag, the Iran war and a provision that would boost Pentagon ties to Israel.
US military marks 11th successive night of attacks on Iran
US Central Command said it completed its 11th consecutive day of strikes on Iran, targeting Iranian military operations centres, maritime capabilities, aircraft hangars, drone storage facilities, and military logistics infrastructure.
US says it reaches nuclear power deal with Saudi Arabia
The US and Saudi Arabia have reached a landmark agreement on civil nuclear power, the US Energy Department said on Wednesday, a deal that allows the kingdom to build nuclear reactors using American technology and to enrich uranium.
Indian opposition disrupts parliament to support student protesters and pressure Modi
Indian opposition lawmakers disrupted parliament on Wednesday in support of student protesters, echoing their calls for the education minister to resign over exam leaks and ratcheting up pressure on Prime Minister Narendra Modi after days of unrest.
