Teething formula tainted with a toxic thickening agent has killed 25 children in Nigeria, prompting regulators to yank it from shelves and shut down its manufacturer, officials said.

The national food and drug administration were scouring Africa's most populous country for about 3,000 bottles of "My Pikin Baby Teething Mixture," which had been inadvertently tainted with diethylene glycol, the agency's head told The Associated Press Wednesday. Eleven other children were being treated after ingesting the compound meant to soothe a teething infant's sore gums, Doris Akunyili said.

"This makes me so miserable. I'm very depressed," said Akunyili. "I found it honestly very pitiable that Nigerian babies are dying this way."

The afflicted children were stricken with fever, convulsions, diarrhea, vomiting and were unable to urinate, Akunyili's agency said.

Diethylene glycol is commonly found in antifreeze and brake fluid and sometimes used illegally as a cheaper alternative to glycerin, which thickens toothpaste. Exposure can cause kidney and liver damage over time. Akunyili said the children died of kidney failure.

The contaminant has been implicated in poisoning cases around the world, including in Panama, where at least 116 people died after taking contaminated cough syrup, antihistamine tablets, calamine lotion and rash ointment made at a government laboratory.

The Nigerian agency said that the manufacturer, Lagos-based Barewa Pharmaceuticals Ltd., has been closed and the formula ordered removed from shelves across the massive nation of 140 million people. A phone number listed for the company was not working Wednesday.

Akunyili said the company's product was normally safe, mixing a pain reliever with a mild antihistamine designed to send the child to sleep. She said investigators were looking at how the diethylene glycol had crept into one batch of the product. She blamed carelessness, not foul play.

Akunyili couldn't say how many bottles of the medicine had been recovered, but she said she was hopeful that no more children would fall ill.

The food and drug agency said the first sickened child was taken for treatment on Nov. 19, in Nigeria's far northern region. Similar cases were documented in subsequent days in Nigeria's densely populated southwest, and investigators isolated the product as common to all the ailing children.

Nigeria has been plagued by tainted, fake or untested drugs since it gained independence from Britian in 1960.

Akunyili said some 200 babies died in 1990 in similar circumstances.

The food and drug administration has drawn plaudits from Nigerians in recent years for having cut down on counterfeit or dangerous medicines. The agency has mostly shut down sprawling fake-drug markets that peddled phony treatments to unsuspecting people unable to afford the genuine article.

Still, some problems persist. Pharmaceutical products that are available by prescription only in many other countries, like anti-depressants, can often be obtained over the counter.

Last year, the food and drug agency ordered the disposal of counterfeit products found to contain the toxic ingredient, diethylene glycol. And in 2005, Nigeria banned the import of pharmaceuticals produced by 30 Asian companies, alleging the firms sent counterfeit and substandard drugs.