By Dan Martin

BEIJING, Sept 17, 2008 (AFP) - Anxious parents rushed their babies in for medical checkups around China on Wednesday, worried and confused over what to feed their babies amid a growing scandal over tainted milk powder.

"I don't know. I really don't know," said An Fengyun, a 34-year-old mother, when asked what she would feed her two-year-old daughter, who whined in her mother's arms for an overdue lunch.

"We are all very worried about this."

An was one of dozens of parents or grandparents who brought babies for checkups at Beijing's Capital Pediatric Research Institute, a children's hospital.

The crowds gathered as Chinese officials confirmed on Wednesday that 21 more companies were found producing milk powder tainted with an industrial chemical. Previously only one company had been blamed.

China said the tainted powder had so far killed three babies and sickened at least 6,244, while checks were being done on all types of dairy products to see if they were similarly contaminated.

In the northwestern province of Gansu, where the scandal first broke, some parents were turning to goat's milk to feed their kids, Qi Yunzhong, a schoolteacher in the city of Wuwei, told AFP by phone.

"For smaller kids, families are finding ways to get them goat's milk. The bigger kids are just eating rice," said Qi, whose own two-year-old son was diagnosed with a kidney stone but is expected to recover.

"We are very angry about this but what can we do?" he said.

Qi said long lines of parents and kids formed daily at the county hospital there.

Outside the Beijing hospital, several parents pored over a newspaper report listing the affected dairy brands and debated what to do.

"We decided to bring her in immediately to be safe. We can't trust any of the milk powder any more," said a woman pensioner who gave only her surname, Ma, holding her 10-month-old granddaughter, Tang Ziqi.

When a young mother suggested switching to only fresh milk, she was shouted down by others.

"How do we know the milk itself is not tainted? This is still being investigated. You can't be too sure!" said an elderly man tending to his toddler grandson.

The chemical blamed for the contamination was melamine, normally used in making plastics, glues and industrial resins.

China's state-run press has suggested it was put into watered down milk to give the appearance of higher protein content.

It has been blamed for causing kidney stones in babies, a condition rare for infants but which causes a range of serious health risks.

An's daughter checked out fine, but to keep it that way, she was considering depriving the toddler of all dairy-based products until the danger had passed.

"It will be difficult because she likes milk. But it is the only way," she said.

Ye Qian, 25, who is six months pregnant and keen to continue drinking milk herself to aid her baby's development, said she was considering the previously unthinkable: consuming only expensive imported milk.

"Hopefully this will be over by the time the baby is born," she said as she shopped in the dairy section of a local supermarket, its shelves thinned out by the recall that morning of three additional brands.

"I'll buy imported milk. It will be more expensive but safer."

Still, she had her fears. The powdered milk she had been consuming through her pregnancy was among the 22 tainted brands.

"I'll never drink that again," she vowed.