A village in northern Germany was in a state of shock on Thursday, a day after police detained a 31-year- old mother on suspicion of killing her five sons aged from 3 to 9, according to dpa. "It's a tragedy, I don't know how such a thing could happen," said neighbour Karl Foerst, whose frontdoor looks on to the garden of the house where the family lived in the tiny community of Darry. Parents wept as they accompanied their children to the local primary school where they were told that classes had been cancelled for the day. "We have four pastors and a school psychologist looking after the children," said Andrea Denker-Isemer, director of the school attended by the two oldest of the dead boys. "It will take a long time for the adults and the children to come to terms with what has happened," said Pastor Gudrun Boelting. An autopsy showed the five boys had been suffocated with plastic bags, apparently after being sedated with tablets by their mother, prosecutors said. The bodies were found Wednesday afternoon in their single-family home in Darry, a village with a population of 450 near the Baltic coast, 30 kilometres east of Kiel. The mother herself called police. She was detained at a psychiatric institution, and her motive appeared to be an effect of mental illness, people involved with the case said. Neighbours placed flowers in front of the white-brick house on Thursday. In the unkempt garden, children's toys stood alongside a kiddies' slide and swings. Uncollected rubbish piled up outside and a newspaper extended from the letter box of the home the family moved into just three months earlier. "They weren't wealthy, but you can't say they were neglected," said a 33-year-old mother in response to reports the children had stale bread to eat and came to school on cold days without jackets. Welfare staff had had an appointment to inspect the family on Wednesday. An 11-year-old girl said she often accompanied the two oldest boys, Jonas and Justin, on their way to school. "One time one of them came out of the house wearing his slippers, but that was only because he forgot to put his shoes on," she said. Neighbours said the father of the three youngest children was from the United States. The father of the other two children lived nearby, in the city of Kiel. Neither was in the house at the time. Two of the children were reportedly handicapped. Neighbours said the children were lively and often played in the garden. "The boys were polite and friendly," said local councillor Hans- Adolf Oden. "They were attentive and always said hello," he added. The mother was rarely seen in the village, but the father often went out with the boys, said another neighbour. In a separate case, German police were holding a 28-year-old woman on serial infanticide charges after finding the remains of three newborns on an apartment balcony in the town of Plauen, halfway between Berlin and Munich in the state of Saxony. Police said she told interrogators she had given birth to three daughters, in February 2002, January 2004 and September 2005, and in each case the infants had "died suddenly" soon after birth. Last year, a woman in the east German town of Brieskow-Finkenheerd was given a 15-year jail term for killing nine of her 13 babies and buryng their bodies in containers filled with earth. Family Affairs Minister Ursula von der Leyen, herself a mother of seven, called the latest cases "a tragedy" and said investigations needed to be conducted to see if there were indications something was wrong.