A major fire broke out on Saturday at Iran's notorious Evin prison, known for housing political prisoners, journalists and foreign nationals.

Videos shared online showed flames and smoke at the prison in Tehran, and gunshots and explosions could be heard.

An official quoted by state media said the situation was under control, but video footage appeared to show the fire continuing after that.

Iran has been gripped for weeks by anti-government protests which first erupted last month after the death of 22-year-old Kurdish Jina (Mahsa) Amini in police custody.