Grieving relatives are angry at the school authorities 
 
 Police in India have arrested the head teacher of a school where 23 children died after eating food contaminated with insecticide last week. 
 
 Meena Kumari had been sought since the tragedy in eastern Bihar state. She handed herself in on Wednesday. 
 
 Police believe she can help explain how the deadly insecticide monocrotophos ended up in the free school lunch. 
 
 In all, 47 primary school children fell ill after consuming the meal of rice and soybeans. 
 
 The Mid-Day meal scheme, introduced to combat hunger and boost school attendance, provides free food for 120 million children in 1.2 million schools across India. 
 
 It often suffers from poor hygiene, and poisoning outbreaks occur from time to time, although rarely if ever with such deadly results. 
 
 All of the teachers in Bihar's state-run primary schools have vowed not to participate in the scheme from Friday. 
 
 "Teachers and the headmasters have to manage the scheme with little help, low-quality food and corruption at every level," said B Sharma, head of the primary school teachers' association. 
 
 "But when such an incident happens, a teacher or the principal is held responsible." 
 
 'Dodgy' 
 
 Earlier, police said scientific tests had detected "very toxic" levels of the pesticide monocrotophos in the deadly meals. 
 
 Vegetable oil used to prepare the food was revealed to be highly contaminated. 
 
 "It was the high quantity of monocrotophos insecticide found in the food which proved fatal for the schoolchildren," said Ravindra Kumar, a top police official in Bihar state capital Patna. 
 
 The school's cook, Manju Devi, had earlier accused the school principal, Meena Kumari, of forcing her to use the oil, despite the cook complaining that it "smelled strongly" and looked "dodgy". She said she was told the oil was "home-made and safe to use". 
 
 State Education Minister, PK Shahi, said it had been bought from the grocery store run by the teacher's husband. 
 
 Police have also been investigating whether the oil was kept in a container previously used to store pesticide. 
 
 Demonstrations following the deaths have spread to the Indian capital 
 
 Reports say Meena Kumari was on her way to the court to hand herself in on Wednesday, but officers stopped her and arrested her before she could go inside. 
 
 She faces charges of murder and gross negligence, according to police. 
 
 "We have arrested her for questioning," said Sujeet Kumar, the police chief of Saran district, where the children died. 
 
 He told the AFP news agency "we need to talk to her first" before bringing charges. 
 
 Bihar Chief Minister Nitish Kumar and other state officials have been criticised for being slow to respond to the tragedy. 
 
 "I assure you, those found guilty will be taken to court and punished," he told a news conference shortly after the arrest. 
 
 Locals complained that it took days for any top-level official to visit the village of Dharmasati Gandaman, where the poisoning occurred on 16 July. 
 
 There have been widespread protests following the deaths and children across India have reportedly been refusing school meals. 

 Story highlights "Every aspect of the case will be investigated," Bihar's chief minister says 
 
 Police say headmistress Meena Kumari was taken into custody on her way to a court 
 
 Authorities say her school served toxic lunches, killing 23 students 
 
 Police also want to question her husband in connection with the case 
 
 The headmistress of the Indian school that authorities say served toxic lunches, killing 23 students, was arrested Wednesday, police said. 
 
 Meena Kumari, 36, was taken into custody on her way to a court where she had gone to surrender herself, police Superintendent Sujeet Kumar told CNN. She will be questioned Wednesday and taken before the court Thursday, he said. 
 
 Authorities had been working to track down Kumari, who had been at large since the July 16 incident. 
 
 The whereabouts of her husband, who is not named as an accused person in the case, are still not known, Kumar added. Police want to question him in connection with the case. 
 
 Forensic scientists found monocrotophos, an organophosphorus compound used as an insecticide, "in the samples of oil from the container, food remains on the platter and mixture of rice with vegetables in an aluminum utensil," Assistant Director General Ravinder Kumar told reporters in Patna. 
 
 Photos: Deadly school lunch in India Photos: Deadly school lunch in India Deadly school lunch in India – A woman rests with her child at a ward housing the poisoned schoolchildren at the Patna Medical College and Hospital, in the eastern Indian state of Bihar, Wednesday, July 17. At least 22 schoolchildren died in northeastern India after eating free school lunches that contained an insecticide commonly used in agriculture. Officials are investigating whether the poisoning was accidental or deliberate. Hide Caption 1 of 6 Photos: Deadly school lunch in India Deadly school lunch in India – Books, papers and dishes are seen scattered on the floor after the incident. Hide Caption 2 of 6 Photos: Deadly school lunch in India Deadly school lunch in India – An Indian man mourns as he holds his dead daughter inside an ambulance, outside a hospital in Patna. Hide Caption 3 of 6 Photos: Deadly school lunch in India Deadly school lunch in India – The deaths triggered violent protests in Chhapra, the headquarters of Saran district. Hide Caption 4 of 6 Photos: Deadly school lunch in India Deadly school lunch in India – A grief stricken mother is consoled after the death of her son. Hide Caption 5 of 6 Photos: Deadly school lunch in India Deadly school lunch in India – Villagers gather for a funeral for children who died from the poison. Hide Caption 6 of 6 
 
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 Monocrotophos, which is used for agricultural purposes, is toxic to humans. 
 
 Bihar's chief minister, Nitish Kumar, vowed that police would investigate the poisoning incident from all possible angles. 
 
 "It does not appear to be mere coincidence or negligence," he told reporters after Kumari's arrest. "Police investigation will reveal everything." 
 
 The chief minister said forensic tests showed that pesticide levels in the food concerned were too high. 
 
 "The main accused (principal Kumari) is now under arrest, and every aspect of the case will be investigated," he said. 
 
 The child survivors of the incident were hospitalized in stable condition, and Nitish Kumar said he had advised that they be kept under medical care longer. 
 
 A cook, Manju Devi, was also hospitalized after eating the food she prepared, doctors said. 
 
 Devi told police that the headmistress did not heed her warning that the mustard oil used to prepare lunch looked and smelled bad. Instead, the headmistress insisted she continue preparing the meal, officials said. 
 
 Authorities previously said police would ensure the headmistress' safety when she was found. 
 
 The children's deaths prompted angry demonstrations from residents. 
 
 In acts of protest, parents of at least three victims have buried their children near the government-run school -- one right in front of the building, according to officials.
– The headmistress at the school where 23 children died after eating insecticide-tainted food has been arrested, the BBC reports. Meena Kumari, who allegedly forced students to continue eating even after the quality of the meal was questioned, fled after the deaths but was headed toward court to turn herself in today when police arrested her. The police chief tells AFP she will be questioned, adding, "We need to talk to her first before framing charges." The 36-year-old will appear in court tomorrow, CNN reports. Police also want to speak with her husband, but his whereabouts are not currently known. Ingredients for the meal, including the tainted oil, were kept in the couple's home, which was raided last week.