Holiday shoppers should avoid toys with small parts that come off — checking them by hand before buying — because children could choke on them, consumer advocates said in an annual toy-safety warning.

Last year, 11 children under age 15 died of toy-related injuries — all but one caused by choking on small balls, balloons, pieces of a game and or toy beads, according to the Consumer Product Safety Commission (search), a federal safety agency.

The U.S. Public Interest Research Group (search), in its 19th annual toy safety survey released Tuesday, again warned that the greatest danger to children still comes in the form of small balls, uninflated or pieces of balloons and toys with parts small enough to choke on. Such toys remain widely available, and often are not labeled as hazardous, the group said.

"Parents should not assume that all toys on store shelves are safe or adequately labeled," said Lindsey Johnson, a consumer advocate for U.S. PIRG's Education Fund and author of the "Trouble in Toyland" report.

The Toy Industry Association (search), whose more than 300 members account for 85 percent of sales, says on its Web site that government reviews of toys on consumer-group watch lists have found that nearly all meet U.S. product safety standards.

The association also says it has taken a lead role in making sure toys are safe by developing standards and educating members and consumers. "This is addressed continuously throughout the year — not just in the busy holiday buying season," the statement said. A spokeswoman was not immediately available for comment on PIRG's toy safety report.

One toy of particular concern, Johnson said, is the "yo-yo water ball" (search) — a water-filled ball on an elastic-like cord that can be bounced, squeezed or twirled overhead like a lasso. The toy has been the source of nearly 400 injury reports to the CPSC, said agency spokesman Ken Giles. U.S. PIRG said suffocation injuries accounted for almost 75 percent of the injury reports after the cords wrapped around a child's neck, with other reported injuries to the eyes, face and head.

Johnson said the toy should be banned from sale in the United States, but the CPSC does not yet agree.

"It's just a matter of time before a child dies," she said.

In September 2003, the federal agency warned of a "low but potential risk" of playing with yo-yo water balls, but stopped short of banning them — an assessment that has not changed, Giles said.

"Even though we have more incidents, nothing has qualitatively changed," he said Monday.

In its warning, the agency said it found no toxicity or flammability concerns with the yo-yos' liquid centers. Besides monitoring children at play with them, it also advised cutting off the cords or throwing away the toys.

Johnson said parents should know that the CPSC does not test all toys, and shouldn't consider a toy to be safe because it's for sale. Even toys that meet federal requirements may still pose dangers, she said.