The baby of Shamima Begum, a British-born teenager who fled London to join the IS, has died in Syria.
The death has been confirmed by the US-backed Syrian Democratic Forces, who declined to specify how or when it happened.
According to the medical certificates obtained by the BBC, the three-week-old boy died of pneumonia.
Shamima, who was stripped of her UK citizenship despite her wish to return, had previously lost two other children, apparently from illness and malnutrition.

Netanyahu says Iran no longer has uranium enrichment capacity
US objectives in Iran have not changed, says Hegseth
Trump vows no more attacks by Israel on Iran gas field
Trump hails Japanese leader, says Tokyo 'really stepping up to the plate' on Iran
Israel reopens key Gaza crossing amid new truce push
