International doctors and healthcare workers report they’re increasingly being blocked by Israel from entering Gaza, with specialists approved for exits but denied new entry visas in what advocates are calling an “undeclared medical siege.”

On Wednesday, U.S. trauma surgeon Dr. Feroze Sidhwa testified to the U.N. Security Council about his time spent as an emergency doctor at the European Hospital in Gaza, where he treated young children severely injured by explosives.

Dr. Feroze Sidhwa: “Children are supposed to be protected. In Gaza, these protections are simply gone. Every day, the distinction between combatant and civilian is erased. Most of my patients were preteen children, their bodies shattered by explosives and torn by flying metal. … The medical system has not failed. It has been systematically dismantled through a sustained military campaign that has willfully violated international humanitarian law. Civilians are now dying not just from the constant airstrikes, but from acute malnutrition, sepsis, exposure and despair.”