TOKYO — Japan has asked the maker of Crocs to look into changing the design of its footwear after complaints that children wearing the colorful plastic clogs have had their feet injured on escalators.

The Trade Ministry said Friday it issued the warning after receiving 65 complaints about Crocs and similar products getting stuck in escalators between June and November last year. Most of the cases involved small children.

Similar complaints have come from the United States, too. Crocs is headquartered in Niwot, about 30 miles north of Denver.

The Washington Metro — one of the nation's largest transit systems — has even posted ads warning about such shoes on its moving stairways. The ads feature a photo of a crocodile, which is the company logo, though the signs don't mention Crocs by name.

There are reports from Singapore to Virginia of instances in which children have had toe nails, and even toes, torn off while wearing Crocs-style shoes on escalators.

In Singapore, a 2-year-old girl wearing rubber clogs — it's unclear what brand — had her big toe completely ripped off in an escalator accident last year, according to local media reports.

And at the Atlanta airport, a 3-year-old boy wearing Crocs suffered a deep gash across the top of his toes in June. That was one of at least seven shoe entrapments at the airport last year, and all but two of them involved Crocs, airport officials said in September.

Crocs pointed out that the Japanese government also asked the escalator industry to improve awareness about safety issues.

"The ministry found that there were a number of factors that led to a specific incident in Japan last summer," said Crocs spokeswoman Tia Mattson. "Those included escalator maintenance, footwear and user riding behavior, which they determined was the primary cause of the accident. We continue to be supportive of escalator safety initiatives and we will consider any recommendations the ministry has for footwear manufacturers."

Recent tests by the National Institute of Technology and Evaluation confirmed the spongy footwear can easily get stuck in escalators because of its flexibility and grip, Japan's Trade Ministry said.

The ministry urged supermarkets, railway stations and other commercial facilities to upgrade signs to urge escalator riders to use caution.

The Japanese unit of Crocs has published a statement on its official Web site warning customers to use caution when riding escalators.

About 3.9 million pairs of Crocs footwear were sold in Japan last year, the ministry said.

Learn more: http://www.crocs.com