Canadian food safety officials are testing for melamine in some dairy products made in China currently on store shelves after Hong Kong recalled tainted milk, ice cream and yogurt Thursday from a Chinese dairy linked to the deaths of at least three children.

No illnesses have been reported in Canada.

Health officials in Hong Kong are investigating whether the death of a fourth child is linked to the tainted dairy products.

Milk powder contaminated with melamine has sickened 6,244 children in mainland China with kidney stones, and 158 have suffered acute kidney failure.

Food safety officials in Hong Kong said they were recalling products from Inner Mongolia Yili Industrial Group Co Ltd. after regulatory tests showed eight of its 30 samples, including milk, contained melamine.

Melamine reportedly boosts protein levels in food. The chemical has been found in the urine and kidney stones of sick babies, China's official Xinhau news agency said.

Xinhua reported the latest death was a baby in the far western region of Xinjiang, though a hospital official said it's too early to tell whether the eight-month-old died of complications caused by the tainted formula.

Milk powder from Sanlu Group Co. has been linked to all of the known illnesses. Another 21 Chinese firms have been implicated in the scandal.

In Shijiazhuang, China, Sanlu's new chairman and chief executive officer apologized at a news conference Thursday.

Zhang Zhenling said he wanted to "express deepest apologies" for the tainted milk powder and for "harm and losses to consumers." He also bowed three times.

Meanwhile, police in Hebei province, where Sanlu is based, said they were launching a 10-day investigation into melamine contamination. Twelve more people were arrested Thursday, raising the total detained in the scandal to 18. Police also seized 222 kilograms of melamine.

Melamine is also used in fire retardants and other industrial products and was found in pet food exported by China, which last year killed hundreds of cats and dogs in Canada and the United States.

With files from the Associated Press