A doctor has been arrested in India following the deaths of at least 12 women who underwent surgery as part of a government-run sterilisation programme, a senior medical official said.
The cause of the deaths was not immediately clear, but officials said the victims showed signs of toxic shock, possibly because of dirty surgical equipment or contaminated medicines.
Tablets linked to the deaths of more than a dozen women at a "sterilisation camp" in India are likely to have contained a chemical compound commonly used in rat poison, a senior official said.
Siddhartha Pardeshi, chief administrator for the Bilaspur district, told Reuters preliminary tests of the antibiotic ciprocin tablets were found to contain zinc phosphide.
Samples have now been sent to laboratories in Delhi and Kolkata to verify that they were contaminated.
"But, this is what we anticipate. Symptoms shown by the patients also conform with zinc phosphide (poisoning)," Mr Pardeshi said.
At least 15 women have now died but more possible victims arrived at hospitals on Thursday and Friday after complaining of vomiting, dizziness and swelling, hospitals officials said.
The state government has seized 200,000 tablets of Ciprocin 500 and over 4 million other tablets.
Police have arrested doctor Ramesh Mahawar, whose firm manufactured the drugs, and his son. The pair claim they are innocent and are victims of a set up.
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Dr RK Gupta has said his supply of post-op drugs was contaminated after being arrested for the deaths of 13 women in a mass sterilisation.
Women who survived a botched mass sterilisation in India which left 12 others dead have told ITV News what they think went wrong.
Eleven women have been killed and others are in a critical condition in India after sterilisation operations were apparently botched.