The government is being urged to find "humane" places for the children of asylum seekers held in detention.
Yarl's Wood in Bedfordshire is one of a number of detention centres
A group of MEPs visiting UK centres expressed concern about the regimes in which children were held.
However, they said conditions at Yarl's Wood, Bedfordshire, Oakington in Cambridgeshire and Harmondsworth, near Heathrow, were generally good.
Ministers have argued it would be wrong to separate children of asylum seekers from their families.
Cypriot MEP Panayiotis Demetriou said the group had concerns over the conditions in which children are held.
He said: "It's not an easy thing to send the children from their mother and their family.
Visiting other countries
"It's not humane to see very young children confined in these centres under the rules of safety required to keep control.
"This situation must be dealt with by the authorities."
MEP Sarah Ludford also criticised the housing of asylum seekers with foreign criminals awaiting deportation.
She said: "Children should not be detained in immigration removal centres.
"It's problematic to confine ex-offenders with people who have not committed a criminal offence."
The MEPs, from the European Parliament committee on civil rights, justice and home affairs, are visiting a series of European countries to examine how they deal with immigrants.
Their full report is expected in the new year.