Two Hong Kong students will undergo surgery after being stabbed at a public housing estate, with police investigating the cause of their injuries. A police source said on Wednesday that the two 18-year-old students were injured after celebrating one of their birthdays on the staircase of the 37th floor of Mei Yue House in Shek Kip Mei Estate the previous day. One student, surnamed Au, suffered knife wounds to his head, back and waist, while the other, surnamed Cheung, sustained injuries to both...