JAKARTA : Indonesia is locking up hundreds of child asylum-seekers and migrants in squalid detention centres where they are sometimes assaulted, Human Rights Watch said on Monday.

They are held alongside adults in centres where detainees are tied up, gagged, beaten with sticks, burned with cigarettes and given electric shocks, the rights group said in a new report.

The world’s most populous Muslim-majority nation is a common transit point for asylum seekers, normally hoping to reach Australia by boat, but many are caught by the authorities. They include children who risk “life and limb” to flee violence and poverty from countries such as Somalia and Afghanistan, only to find themselves locked up in detention centres in Indonesia, said the rights group. “Each year, hundreds are detained in sordid conditions, without access to lawyers, and sometimes beaten,” said Human Rights Watch.

“Both adults and children described guards kicking, punching, and slapping them or other detainees.”

More than 1,000 unaccompanied children arrived in Indonesia last year, the rights group said in the report, for which it interviewed 42 people who were children when they came to Indonesia, as well as immigration officials and NGOs.

While many are held in detention centres, others are left on the streets with no legal or material assistance, as there is no government agency responsible for their guardianship, said the report.

The group urged Indonesia to clean up its detention facilities — which it said were often overcrowded and unsanitary — and institute fair and thorough processing for asylum seekers.

“Desperate children will keep coming to Indonesia, and the government should step up to give them decent care,” said the group’s children’s rights researcher Alice Farmer.

But Indonesian immigration official Subandriyani, who goes by one name, described the claims in the report as “untrue and baseless” and said guards would not dare abuse detainees as they would be sacked.

“We make routine checks at detention centres and we try our best to uphold human rights,” he told AFP. However, he admitted there were problems of overcrowding at some centres.