Human rights groups and local authorities have criticized Greece for the poor conditions at the country’s biggest migrant camp, Moria, currently operating at almost three times its capacity.

About 9,000 migrants and refugees are holed up in the camp, a collection of tents and shipping containers in a former military base, according to the latest government data.

A local governor threatened to shut it down within 30 days unless authorities clean up uncontrollable amounts of waste.

“The situation in Moria really is difficult,” government spokesman Dimitris Tzanakopoulos told a briefing. “It really is borderline.”

Some 3,000 people were transferred from Moria to the mainland over the summer and another 700 people were moved last week, Tzanakopoulos said. A further 2,000 would be moved by the end of September, he said.

Europe’s top migration official, Dimitris Avramopoulos, is expected to visit Athens this week for talks with Prime Minister Alexis Tsipras.

Last week, over a dozen human rights groups urged Greece to take action to render its camps fit for human habitation.

Medical charity Medecins Sans Frontieres (MSF) said on Monday it had witnessed an unprecedented health crisis in Moria, where it found many teenagers had attempted to commit suicide or were harming themselves on a weekly basis.