LOS ANGELES — Detained migrant children must be given soap, dry clothes and clean bedding, US federal judges ruled on Thursday, dismissing an appeal by the Trump administration.

The ruling by three judges at San Francisco's federal appeals court follows reports of severe overcrowding and disease-ridden cells at US detention centres.

A surge of Central American migrants has overwhelmed US immigration services, leading to multi-pronged controversial efforts by US President Donald Trump's administration to stem the flow, resulting in court challenges.

The panel found that basic hygiene items and adequate sleeping arrangements were essential under a 1997 law requiring "safe and sanitary" facilities.

In doing so, they upheld an earlier ruling by a lower court which found the government was in breach of its obligations by failing to provide these.

The Department of Homeland Security had appealed that ruling, arguing that the "safe and sanitary" law did not specify that any of these items be provided.

"We emphatically disagree," the judges said in their judgment on Thursday.

"Assuring that children eat enough edible food, drink clean water, are housed in hygienic facilities with sanitary bathrooms, have soap and toothpaste, and are not sleep deprived are without doubt essential to the children's safety," they wrote.

The lower court ruling in 2017 was right to require such conditions "rather than allowing the government to decide whether to provide them," they found.

Last month, the UN human rights chief said she was "deeply shocked" by conditions under which migrant children were held at US detention centers.

"As a pediatrician, but also as a mother and a former head of State, I am deeply shocked that children are forced to sleep on the floor in overcrowded facilities, without access to adequate health care or food, and with poor sanitation conditions," Michelle Bachelet, the United Nations High Commissioner for Human Rights, said in a statement.

Trump has described reports of hundreds of children wearing filthy clothing and packed into disease-ridden cells at a Texas border camp as a "hoax." — AFP