Eight young children were injured yesterday in an attack by a staff member at a day-care centre for the children of migrant workers in a Shanghai suburb. The injured children were taken to the Children's Hospital of Fudan University, about 10 kilometres from the centre. Four of them were seriously injured and one was in critical condition last night, local media said. The Xinmin Evening News reported that the attacker was a woman member of staff, originally from Anhui province. She was said to have been armed with a box-cutter knife, but the People's Daily reported online that she injured the children with a metal ruler. Police took her into custody. The Little Lucky Stars Childminding Centre is located in a large and free-standing three-storey house in a back street in Minhang district, in the far northwest of Shanghai. The rundown neighbourhood is home to a large number of migrant workers employed in nearby factories. Yesterday afternoon the alley had been cordoned off by police. A large crowd of parents and residents gathered in the street, shocked and angry about the incident and frustrated about the complete lack of reliable information. 'Nobody from the school told us about the attack. I just heard rumours going around the factory that something had happened, and I raced over to collect my son,' said one father, carrying his four-year-old boy. The boy was unharmed in the attack, but a large bloodstain ran down the front of his clothes. 'He won't say a word about what happened,' said the father, who declined to give his name. 'He is in shock. It scared him half to death. I want to know how this happened, but the school and the police won't tell us anything. Everyone says it was a teacher who hurt the children and that she had mental problems - if that is true, how could she be allowed to look after our children?' One mother, originally from Anhui, said her six-year-old daughter had been taking her after-lunch nap on the upper floor of the house when the attack occurred. 'I asked her what happened, and she said she went down the stairs to find all the children crying loudly,' she said. 'She told me there was blood everywhere, all over the floor and covering several children. It sounded horrible.' Locals said the day-care centre, which had been open for about four years, had slightly more than 100 pupils, almost all them children of migrant workers. Shanghai party secretary Yu Zhengsheng and Mayor Han Zheng visited the hospital yesterday afternoon and were taking a personal interest in the case, the Xinmin Evening News reported. No one was available at the hospital to comment on the situation, and security guards and police prevented reporters from speaking to relatives of the victims. Police at the scene and at the hospital declined to comment on the incident, saying it was currently under investigation. Grim toll June 15, 2011 Long Shixu, a 25-year-old student at Xingyi Normal University for Nationalities in Guizhou, kills a roommate by stabbing him in the throat with a watermelon knife, and severely wounds another roommate. Long is still on the run. August 3, 2010 Fang Jiantang, a 26-year-old jobless man, stabs three children to death and injures seven others at a kindergarten in Zibo, Shandong. The kindergarten is said to teach children of civil servants. May 12 Wu Huanming, 48, hacks to death seven young children and two adults and injures 11 other children at a private kindergarten in a village in Nanzheng county, Shaanxi. April 29 Xu Yuyuan, a 47-year-old unemployed man, attacks a classroom of four-year-olds at a kindergarten in Taixing, Jiangsu, wounding 29 of them. Xu is executed a month later. April 28 Chen Kangbing, wielding a knife, breaks into a primary school in Leizhou, Guangdong, and stabs 16 students and a teacher. Chen is sentenced to death. April 12 Yang Jiaqin, 40, hacks to death a second-grader and an elderly woman, and injures five others near an elementary school in Xichang town, Guangxi. March 23 Zheng Minsheng, 42, kills eight children in a knife attack at Nanping Experimental Elementary School in Fujian. Zheng is executed a month later.