U.S. Sen. Tom Harkin, D-Iowa, says the federal government should keep confidential the location and identities of the 139 undocumented, unaccompanied immigrant children who have come to the state in the last year.

Releasing the information, as some Republicans are demanding of the U.S. Department of Health and Human Services (HHS), would expose the kids to politically charged abuse, Harkin said on a conference call with the media this morning.

"I know some have criticized the president for not being transparent about this, or HHS not being transparent," Harkin said. "There's a reason for that. Remember the incident in California? These kids were on a bus, and we had all these screaming protesters beating on it and telling them they should be sent back."

Harkin said the mayor of Davenport, Bill Gluba, has been threatened for working with Quad Cities churches and other organizations on possible temporary housing for many of the children, part of a wave of more than 50,000 immigrants without documentation - or parents coming with them - to enter the United States since October. Most are from El Salvador, Honduras and Guatemala, nations ridden by narcotics trafficking and violence. The episode has spurred fierce global debate over whether the children should be considered refugees - a term Harkin used to describe them.

"These kids are sent to homes and facilities around the country," Harkin said. "As I have said, the first priority we have is to keep these kids safe, well-fed, housed, and give them an opportunity for asylum. What you don't need is to be making them objects where people can come out and threaten them or bang on buses and stuff like that like they did in California."

Harkin strongly disagreed with the top two elected Republicans from Iowa, Gov. Terry Branstad and U.S. Sen. Charles Grassley, who are pressing the federal government for more details on the children in Iowa.

"Anyone who says that HHS needs to publicly tell where these kids are going, or even where they are at right now, that's wrong," Harkin said. "These kids need to be protected, housed and kept safe."

Harkin added, "I see nothing wrong with them telling a governor that kids are coming to a state. They don't need to tell them where they're going or how many are going."

Branstad told the Daily Times Herald on Tuesday that the Obama administration needs to be transparent in its handling of the matter. But the governor didn't say what he would do with information on names, addresses, legal status and other facts on the immigrants that he says is "reasonable" for Gov. Dave Heinemen to request about the more than 200 such kids in Nebraska.

Harkin said the release of those details is dangerous.

"Maybe some family has taken in two or three of these kids to keep them safe and to feed them," Harkin said. "This is a humanitarian gesture. Churches have done this. Should they now be made public so people can picket their houses or threaten them? There's enough of that out there."

Harkin said the federal government is paying for the care of the kids as they work through the system.

"Keep in mind these kids are not criminals, they're not criminals," Harkin said. "They're refugees. They're kids that are escaping murder and violence and rape and all kinds of bad things."

Harkin said he met Wednesday with the ambassadors of Guatemala, Honduras and El Salvador.

"Things are now being put in place to help stem the exodus of these kids from those three countries," Harkin said.

The Iowa senator said the Central American ambassadors called for U.S. assistance in the form of a Marshall Plan-like response, where as with the rebuilding of post-war Germany, American organizations would help lead with job creation, human rights and development in the region.

The drug and gang activities in the three Central American nations are being used to feed the appetites of American narcotics users, Harkin said.