China said Saturday it had rejected a shipment of pistachios from the United States because it contained ants, the latest indication the government may be retaliating as Chinese products are turned back from overseas because of safety concerns.

The state television report, which showed inspectors wearing face masks and sealing the shipping container that held the pistachios, indicated an increasing push to show that other countries also have food safety issues. On Friday, Chinese food safety watchdog announced that shipments of health supplements and raisins from the U.S. had been returned or destroyed because they did not meet quality control standards.

China's food- and drug-safety record has come under scrutiny in recent months following the deaths of cats and dogs in the United States and Canada blamed on tainted Chinese pet food ingredients. Since then, U.S. inspectors have banned or turned away a growing number of Chinese exports _ from monkfish to juice to toothpaste _ because they contained life-threatening levels of toxins or unsafe chemicals.

In the report Saturday, China Central Television said the ants found in the pistachio shipment could "cause a serious threat to trees and to the ecological environment." Part of the batch, which arrived by ship to the port of Zhongshan, will be destroyed and the rest will be returned, CCTV said, without giving any other details.

The report also showed U.S. safety certificates issued to Cal-Pure Pistachios Inc., based near Bakersfield, Calif. Messages left for the company were not immediately returned Saturday.

Telephone calls to Guangdong quarantine officials rang unanswered on Saturday.

The Web site of the General Administration of Quality Supervision, Inspection and Quarantine, China's food safety agency, showed lists of products from 2006 and 2007 that had been turned away from countries including the United States, Canada, Japan, Singapore and Italy because they did not meet Chinese standards.

France's Groupe Danone SA says China seized five containers of Evian water in February because of concern over high bacteria levels.

A U.S. Food and Drug Administration official said Friday that the U.S. is seeking more information on the latest cases of American products being turned away.

"Whatever the motives are for this, if it's real, we want to know about it," said David Acheson, assistant commissioner for food protection at the FDA.

An international outcry about has China's safety record has the government worried that its goods could be banned from overseas markets. The country's dismal drug safety record was underscored this week by a Chinese court's decision to sentence to death the country's former top drug regulator.

"Is it tit-for-tat? We don't know and probably won't ever know," Acheson said. "If they found a legitimate problem with a product exported from the United States, we would want to know about it so we can look into it and fix it."

Chinese regulators have urged local authorities to step up inspections of imported food products and said Chinese importers should "clarify food safety demands in contracts when importing U.S. food products, so as to lower the trade risk."