Another 14 women are seriously ill in Chhattisgarh state after the surgery, which women are paid 1,400 rupees to have under a government scheme to reduce population growth.
"Preliminary examinations suggest septic shock may have caused the deaths," said local government official Amar Thakur.
"It looks like the equipment that was used was probably infected. We are waiting for the report," he told AFP by telephone from Chhattisgarh's Bilaspur district, where around 80 women had the surgery over the weekend.
The victims had suffered vomiting and a dramatic fall in blood pressure after undergoing laparoscopic sterilisation, a process in which the fallopian tubes are blocked.
As the death toll rose to 13 on Wednesday, a local official said women who attended a second sterilisation camp in the area on Monday had also fallen ill.
"Six women from Gorella camp developed complications and they have been brought to Bilaspur for treatment," district commissioner Sonmani Borah told AFP.
Shops and businesses shut their doors in the state capital Raipur on Wednesday as scores of demonstrators took to the streets to demand the resignation of Chhattisgarh Chief Minister Raman Singh.
Television footage showed the protesters, many of them opposition party workers, chanting slogans and smashing up vehicles.
Sterilisation is one of the most popular methods of family planning in India, and many state governments organise mass camps where rural women can undergo the usually straightforward procedure.
Although the surgery is voluntary, rights groups say the target-driven nature of the programme has led to women being coerced into being sterilised, often in inadequate medical facilities.
Under pressure to meet targets, some local governments offer additional incentives such as cars and electrical goods.
In the latest case, one doctor reportedly operated on 83 women in just five hours, using the same instruments on all of them. Some of the women also said they had been forced to attend the camps, according to local media.
Sona Sharma, joint director at advocacy group the Population Foundation of India, said the quality of care provided to women undergoing sterilisation is "abysmal".
"It is about time we woke up to this problem. The quality of care to women can't be compromised at any cost," she told AFP.
"The government has laid out standard protocols, but they exist only on paper," she said, urging the government to adopt a "more choice-based voluntary system" of family planning.
Last year, authorities in eastern India came under fire after a news channel unearthed footage showing scores of women dumped unconscious in a field following a mass sterilisation.
Prime Minister Narendra Modi has ordered an investigation into the latest deaths, and Chief Minister Singh on Tuesday suspended four top health officials.
A police complaint has also been lodged against the surgeon who performed the operations.
Reports said the doctor had been given a government award earlier this year for performing tens of thousands of such sterilisations.
COMMENTS (4)
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The crux of the problem is this. When the government provides some assistance or gives anything free to the needy and deserving, the officers who disburse the assistance think that they are giving it out of their pocket and that those receiving assistance are just after freebies. They treat the recipients demeaningly with disgust and contempt. It is this attitude that is behind the negligence and total neglect by these medical professionals. There had been many instances where patients have gone blind after undergoing free cataract surgeries in government organized eye camps solely due to this attitude that results in negligence of the medical staff.
@Hashk03: What does one have to do with the other ?
National shame
Just a right time to send another probe to Mars and see if there is any methane gas over there for future use also try to study at the same time about origins of life in the same mission.
Does it seems right or wrong?