A mysterious injury suffered by a 16-year-old girl who boarded a Metro train in Iran’s capital without a headscarf has reignited anger just after the one-year anniversary of the death of Mahsa Amini and the nationwide protests it sparked.

What happened in the few seconds after Armita Geravand entered the train on Sunday remains in question. While a friend told Iranian state television that she hit her head on the station’s platform, the soundless footage aired by the broadcaster from outside of the car is blocked by a bystander. Just seconds later, her limp body is carried off.

Geravand’s mother and father appeared in state media footage saying a blood pressure issue, a fall or perhaps both contributed to their daughter’s injury.

Activists abroad have alleged Geravand may have been pushed or attacked because she was not wearing the hijab. They demand an independent investigation by the United Nations’ fact-finding mission on Iran, citing the theocracy’s use of pressure on victims’ families and state TV’s history of airing hundreds of coerced confessions.