One person was killed and up to 19 others injured when an explosion ripped through a busy pedestrianised area in Tongren city, Guizhou province on Thursday, local media and witnesses said. An official at Tongren municipal public security bureau said the bomb went off at about 1pm near Minzhu Road. She said the cause of the blast was still being investigated and there had been no arrests. There was no further information about the person killed in the blast. Analysts have pointed to the increasing trend in China of disillusioned individuals - mostly the underprivileged in a society rapidly polarising between rich and poor - resorting to violent acts such as planting bombs or poisoning people to vent their grievances. An official with the municipal party committee said five people had been seriously injured, while the rest suffered only minor wounds. He disputed the casualty figure of 19, reported by local newspaper Guizhou Dushibao, saying it was somewhat lower. Neither official would give details of the blast. Witness Wang Meng, 20, a medical student who suffered minor cuts and was treated in hospital, said yesterday that the explosive device was hidden in a rubbish bin by the roadside on the busiest section of the street. He said he was on his way to lunch when he heard a loud explosion. He then realised he was bleeding. 'The steel rubbish bin was shattered by the blast and I was cut by a piece of the steel debris,' he said. 'People were running and there were about 10 people lying on the ground. There were children among them,' Mr Wang said, adding that the street was packed with people on their lunch breaks. 'The blast was quite powerful and there was debris and glass everywhere.' A medic at Tongren People's Hospital said most patients suffered only minor injuries. An 18-year-old boy, Chen Tongfa, was still in serious condition yesterday. A worker at a telephone service company near where the bomb went off said the street was cordoned off yesterday morning but shops reopened in the afternoon when the police allowed people back to work. 'There was still a lot of blood on the street and there was a black spot where the rubbish bin was once placed,' she said, adding that windows of many nearby shops shattered by the blast remained boarded up. Yesterday, the cause of the blast was still unknown. 'Of course, people speculate a lot about the cause of the explosion because this is the first such incident to take place here since 1949,' the telephone worker said. One local resident added: 'There is speculation that this is a terrorist act. Of course, this is only rumour, but people are worried.'