The Greek office of the United Nations refugee agency (UNHCR) yesterday expressed serious concerns about the situation of “dozens of unaccompanied minors” being detained at a substandard migrant reception center on Lesvos.

Many children are said to be in a “poor psychological state,” with some reportedly threatening to go on hunger strikes.

The UNHCR highlighted a series of “problems and shortcomings” with standards of hygiene and facilities at the center. “Clearly there is a need to replace this detention center with other facilities that meet minimum international standards,” an official statement said.

The UNHCR’s Greek office had pushed for the closure of a detention center on the island of Samos that had provoked the outrage of visiting Euro MPs. A new center opened early this year on Samos, while the old one was shut down.

The UNHCR is pushing for priority treatment for unaccompanied child migrants. It has also asked the Interior Ministry to ensure that migrants who lodge asylum applications are not detained until the outcome of appeals, which can take months.