China's tainted milk scandal has worsened, with tests now showing liquid milk is also affected.  Visiting U.S. and European officials in charge of consumer safety have expressed concern about the problem as product recalls continue.  Daniel Schearf reports from Beijing.

China's quality watchdog confirms the toxic chemical melamine was found in 10 percent of the liquid milk sampled from three of the country's top dairy suppliers.

The industrial chemical used in plastics was previously found only in powdered milk after thousands of infants became sick with kidney stones.

The scandal is widening as U.S. and European officials are in China for talks Friday on product safety.

Robert Madelin is the director-general for health and consumer protection for the European Commission.  He says the delegations want a full explanation.

"The issue between governments, between regulators, is, are we being immediately open with each other?" he asked.  "Then there is a duty on economic operators to be open, and there I would expect each regulator to punish delay within their own jurisdiction."

Twenty two Chinese dairies have been found selling products tainted with melamine.  The chemical is high in nitrogen and is believed to have been used in watered-down milk to make it appear higher in protein. 

At least two of the dairies exported to countries in Asia and Africa. 

So far no tainted milk products have been reported outside China.  But in Hong Kong, authorities found tainted dairy products from the Yili group, and were pulling them from the shelves.

Nancy Nord, the acting chairwoman of the U.S. Consumer Product Safety Commission, said Friday the scandal underscores the need for dialogue on safety issues.

"We always have to be very vigilant that we don't see this kind of thing surface in other areas.  That is why it is so very critical that we have these kinds of conversations at the senior levels, at the policy levels, and then at the technical level," she said.  

"We need to make sure that we have got the appropriate lines of communication open so that we can deal with these issues as appropriate when they come up," she added.

So far, four babies have died and over 6,000 made sick after drinking formula made from tainted powdered milk.  No adults have been made sick.

The economic fallout from the scandal is not yet clear, but China's dairy industry is expected to be hard hit.

The coffee chain Starbucks has already said it will stop using Mengniu brand milk in its 300 plus stores in China.

Authorities ordered tainted products to be recalled and vowed to punish those responsible.

Eighteen people have been arrested so far and several dairy company executives have been fired.