Mr Maroni said Roma children would be fingerprinted to avoid "begging"
Italy's interior minister has sparked criticism with a proposal that would see police fingerprinting all members of the Roma community living in camps.
Roberto Maroni, of the anti-immigrant Northern League, said the move would guarantee that those with the right to stay could live in decent conditions.
Those without that right, including children, would be sent home, he said.
The UN Children's Fund (Unicef) has criticised the proposal, as have opposition MPs.
Mr Maroni said the fingerprinting of Roma - or Gypsy - people would include "children too, to avoid phenomena like begging".
Since Prime Minister Silvio Berlusconi was returned to power in elections two months ago, his government has focused on law and order, says the BBC's Christian Fraser in Rome.
The blame for the rising crime has fallen on the Roma gypsy community and, in recent weeks, camps have been raided by police while others have been attacked and burnt by vigilante mobs, our correspondent adds.
Stunned and concerned
Opposition MPs said it was wrong to treat children as criminals.
Rosy Bindi, who held the post of family minister in the centre-left government that was ousted in January, said the initiative was "unacceptable".
It would lead to an "ethnic register" that would "treat Roma children as if they were hardened criminals", she said.
The head of Unicef Italy, Vincenzo Spadafora, said his organisation was "stunned and deeply concerned" by the proposal.
"We'd like to suggest to him (Mr Maroni) that to respect all children's right to equality he should record all Italian children in the same way," said Mr Spadafora.
"Roma children are no different from other children. Moreover children cannot and should not be treated as adults."
Meanwhile, Amos Luzzatto, the former president of Italy's Union of Jewish Communities, said the measure was a form of "ethnic surveying".
"You start like this then you move on to the exclusion from schools, separated classes and widespread discrimination," he said.
Recalling how Jews, Roma and other minorities were targeted during Italy's years of fascism, he accused the country of having "lost its memory".