U.N. experts say water shutoffs at Detroit homes due to overdue bills violate international human rights.

Right to water and sanitation expert Catarina de Albuquerque says Wednesday that disconnections due to non-payment are "only permissible if it can be shown that the resident is able to pay but is not paying."

The statement follows a letter sent this week to the U.N. Office of the High Commissioner for Human Rights by welfare rights groups who complain that mass shutoffs by Detroit's water department are leaving poor people at risk.

Water department spokeswoman Curtrise Garner says service to 4,500 customers was cut last month, but more than half then paid up. Garner says about $90 million is owed by 90,000 active customers who are behind at least two months.