Walid Ahmad was a healthy high schooler before his arrest in September for allegedly throwing stones at soldiers, his family said. Rights groups have documented widespread abuse in Israeli detention facilities holding thousands of Palestinians who were rounded up after Hamas’ Oct. 7, 2023, attack ignited the war in the Gaza Strip.

Prison authorities deny any systematic abuse and say they investigate accusations of wrongdoing by prison staff. But the Israeli ministry overseeing prisons acknowledges conditions inside detention facilities have been reduced to the minimum level allowed under Israeli law.

Israel’s prison service did not respond to questions about the cause of death. It said only that a 17-year-old from the West Bank had died in Megiddo Prison, a facility that has previously been accused of abusing Palestinian inmates, “with his medical condition being kept confidential.” It said it investigates all deaths in detention.