Indian state officials reported on Tuesday that up to eight women have died and dozens of others are ill, some in a serious condition, in hospital following the sterilization surgeries in the central Chhattisgarh state.

A total of 83 women had the tubectomy operations on Saturday at a free government-run camp and it is understood they were sent home that evening.

A local official from the Bilaspur district where the camp was held told the AFP news agency that many of them reported falling sick shortly afterwards.

"Reports of a drop in pulse, vomiting and other ailments started pouring in on Monday from the women who underwent surgery," Sonmani Borah, the commissioner for Bilaspur district, told AFP by phone, adding that eight women had died since Monday and dozens more were in various hospitals.

The Indian Express daily and the Headlines Today news channel reported that the surgeries were carried out over the space of five hours. The Express reported that one doctor and an assistant performed the operations.

Indian authorities are investigating the incident.

The medical superintendent of the main hospital in Bilaspur, where many of the ill women were admitted, told reporters it would be difficult to say what caused the deaths.

"We will know the reasons only once the post-mortem is completed," Ramnesh Murthy said.

State-sponsored surgeries

Local health authorities in India have long been encouraging sterilizations as a means to control the country's booming population, offering incentives like free televisions and cars to couples who volunteer to undergo the procedure.

Bilaspur's chief medical officer R.K. Bhange said the women who had the tubectomies in Chhattisgarh received 1,400 rupees (18 euros, $23) to have the surgery, while health workers received 200 rupees for bringing a woman to the family planning camp.

India's population of more than a billion is predicted to overtake China's by 2030.

se/nm (AP, dpa, AFP)