BEIJING (AP)  A knife-wielding man went on a slashing rampage in a kindergarten in eastern China, leaving three children and one teacher dead in the country's latest school attack, area residents said Wednesday. The official Xinhua News Agency said police had detained a 26-year-old man who had confessed. Officials refused to release details of the attack, saying they feared reports could inspire copycat killers. The assault was among the worst in a spate of gory rampages this year in schools and in public spaces that have left dozens of people dead and scores wounded. The assailant entered the Boshan District Experimental Kindergarten's Jinfengyuan branch in a suburb of Zibo in Shandong province at about 4 p.m. Tuesday as parents were picking up their children, according to people living nearby contacted by telephone. About 20 children and staff members were injured, two of the children seriously, they said. Official news media were largely silent on the attack Wednesday — a sign editors had been told to steer clear of the topic as part of efforts to discourage more violence and calm public fears. Online postings about it were deleted by mid-afternoon by government censors who police the Internet for material considered politically sensitive. RESPONSE: China steps up school security in attacks' wake However, Xinhua issued an English-language report late Wednesday saying police had detained a 26-year-old man on suspicion of killing at least three children. It said self-employed worker Fang Jiantang had admitted committing the attack with a 24-inch (60 centimeter) knife, but his motive was unknown. Assailants in previous attacks have often suffered from mental illness, held grudges against their victims, or were angry over personal failures. Xinhua said three children died at the scene, and three other children and four teachers were taken to a hospital. Two of the teachers were in serious condition, it said. Earlier, the head of the Zibo government propaganda department's news office, who gave just his surname, Bi, would say only that there had been "very few deaths and injuries." "The country has a regulation about reporting on these sorts of reports. There's a worry that they might inspire copycat crimes creating a negative impact, so therefore, we are not issuing a report," Bi told The Associated Press by phone. A woman who works in a restaurant opposite the kindergarten said the attacker was a man aged 27 or 28 who gained entry to the school by posing as a parent. Police rushed to the kindergarten soon after the attack and officers transported some wounded children to a hospital before ambulances had time to arrive, said the woman, who would give only her surname, Zhang. "The kindergarten has been sealed off," Zhang said. "There are still police officers there." Zhang and other area residents said the teacher died of her injuries Wednesday morning. The Zibo killings came just two days after a man driving an earth mover in Hebei province to the west went on a rampage, smashing vehicles and buildings and leaving 17 dead. Other recent mass killings include a May 12 attack on a kindergarten in the northern province of Shaanxi that killed seven children and two adults, and the wounding of 29 children at a kindergarten in Jiangsu province in April. The seemingly unrelated attacks have prompted calls for more attention to diagnosing serious mental illnesses and ignited fears over the toll stress is taking on the nation's emotional health. Copyright 2010 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more