Kenya says it plans to shut down two refugee camps, including the world’s largest, due to security concerns. The announcement was swiftly condemned by human rights groups that say the move puts some of the world’s most vulnerable people at risk.

In a statement, the Kenyan government says it is working to expedite the closure of the Dadaab and Kakuma camps. They’re home to hundreds of thousands of refugees, the vast majority fleeing violence in neighboring Somalia.

The government has made such threats previously. Last year, it announced it was closing the camps but later “backed down in the face of international pressure,” CNN reports.

Image: Half of the population of Dadaab refugee camp is under 18 … refugees at the camp, 8 May 2015. Photograph: Tony Karumba/AFP/Getty Images