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.
India begins voting in election as Modi seeks historic third term
India began voting on Friday in the world's largest election as Prime Minister Narendra Modi seeks a historic third term in office on the back of growth, welfare, his personal popularity and Hindu nationalism.
Teenager charged with terrorism over Sydney bishop stabbing
A 16-year-old boy has been charged with a terrorism offence for allegedly stabbing an Assyrian church bishop in Sydney during a church service, Australian police said on Friday, as investigations continued into a riot after the knife attack.
Kenya's military chief among 10 killed in helicopter crash
Kenya's military chief, General Francis Ogolla, was among 10 people killed when their military helicopter crashed shortly after take-off on Thursday.
Security Council to vote on Palestinian UN membership
The UN Security Council is due to vote on Thursday on a Palestinian bid for full UN membership.
Toll from Russia's deadliest airstrike on Ukraine in weeks rises to 18
The death toll from a Russian airstrike on Chernihiv in northern Ukraine has risen to 18, officials said on Thursday, while another 78 were wounded when three missiles slammed into the city centre.
