Bhopal, March 15 (IANS) The anti-measles vaccine that killed four babies in Madhya Pradesh's Damoh district last week turned a killer because it was used over three hours after being mixed, a health official said Monday.

The samples of the vaccines were sealed and sent to New Delhi for examination and the vaccination programme was suspended.

While the report from New Delhi was yet to come in, health department director A.N. Mittal, who visited Damoh, said: 'The vaccine shots given to the children had turned poisonous because they were administered over three hours after its powder was mixed with the solvent'.

Four babies died and 16 were taken ill Saturday after they were administered anti-measles shots at a government health centre in Damoh district. Nurse Durga Tiwari was arrested on charges of negligence and district vaccination officer Anupam Kulshreshta and LHV vaccination centre's S. Nayak were suspended.

The victims were identified as Arti Thakur, Gaurav Vishvakarma, Roshni Gond and Arman Vishwakarma.

While the post-mortem examination reports of the infants revealed that they died of toxic shock syndrome, a rare and unforeseen snag following measles vaccination, the parents of the victims said the babies started frothing at the mouth and nose, turned blue and died within 12 hours of being given the vaccine. In all, 20 infants were administered the vaccine.