Security is on high alert at this train station in southwestern China.<br/> <br />Armed riot police stood guard as people streamed into the Kunming station in Yunnan province. It's been just hours after a chilling mass knife attack left at least 29 people dead and more than 130 injured.<br/> <br />Witnesses say a group of knife wielding attackers burst into the station and began stabbing people at random.<br/> <br />(SOUNDBTE) (Mandarin) PARKING ATTENDANT MR. CHEN STANDING SAYING:<br/> <br />"Two women said to me: 'There's fighting outside, they're killing people'. I said: 'Don't talk nonsense, it's very safe here'. But that people really were being killed. So I walked out and I saw a person with a knife this big. I thought it was just one person, so I planned to shout for a couple of people to try and apprehend them, but then I saw five or six of them. They all had knives and they were stabbing people madly over by the first and second ticket offices."<br/> <br />(SOUNDBITE) (Mandarin) SUPERMARKET WORKER REN
