Police in south-western China have discovered 28 baby girls packed into nylon suitcases and stacked on the luggage rack of a long-distance bus.
The police, acting on a tip-off, found them at a highway toll gate in Binyang, Guangxi province.
One of the babies - some of whose cheeks were mottled with cold - had died by the time the discovery was made on Tuesday evening.
The Beijing Morning News newspaper published the story on Saturday and it has since been confirmed by police.
Police said the youngest of the babies were only a few days old and the eldest were no more than three months. Most were "fine", they said.
They had been taken to a nearby school where nurses were taking care of them.
The newspaper suggested the infants may have been drugged to stop them crying.
"They had been on the bus for four or five hours before they were found," a police man told news agency AFP.
The babies, some packed two or three to a suitcase, were stacked on the luggage rack, on the back seat and along the sides of the bus, which was bound for an eastern province.
More than 20 suspects have been arrested, a police officer told AFP.
"Most of the people arrested were middle-aged women from Binyang. They probably wanted to make some money," he said. Guangxi is one of the country's poorest areas.
No one had so far claimed the babies.
"It's possible the parents gave the babies away. Family planning policy is very strict and they probably had exceeded their birth limit and wanted to give the babies away to avoid fines," the officer said.
"Perhaps some of them were born to unwed mothers or migrant workers."
Child smuggling is a grave problem in China, with cases regularly reported. Babies may be sold to families with few or no children.
And in a country where boys are traditionally valued over girls, older girls or women may be sold to poor farmers as brides, or to men in provinces with few women.