Rights groups on Thursday expressed renewed concerns about the humanitarian situation in Gaza after Israel’s latest evacuation orders in parts of the overcrowded central city of Deir al-Balah.

The polio virus has been circulating in the battered Palestinian enclave for the first time in 25 years, relief organization the International Rescue Committee said in a statement. It said the spread resulted from the destruction of hospitals and water infrastructure, along with overcrowded living conditions.