Authorities in India ordered an investigation Friday after at least 24 poor and elderly people went blind following cataract surgeries performed at a free medical camp run by a charity in the country’s north.

The botched operations drew further attention to the poor state of health care in India, which has one of the lowest rates of public spending on medical care anywhere, according to the World Health Organization.

The operations were performed in early November on 130 patients who were all older than 50 and living in either Amritsar or nearby Gurdaspur, in Punjab state, said Abhinav Trikha, a top official in Gurdaspur.

Some of the patients reported this week that they'd lost their eyesight or were suffering infections, top Amritsar official Ravi Bhagat said.

Doctors in Amritsar were treating some of the patients on Friday, but said it was unlikely any would regain their sight. Police have launched an investigation, and detained at least one doctor in Gurdaspur.

Every year, millions of poor Indians without access to doctors or health insurance are forced to seek treatment at medical camps because of poor services and corruption at government hospitals.

Last month, 13 women died after allegedly taking tainted drugs after undergoing simple sterilization surgeries in the central state of Chhattisgarh.

Al Jazeera and wire services