Baby of British ISIS woman Shamima Begum has died

The infant son of a British-born woman who ran away from home to join ISIS has died, a spokesman for the Syrian Democratic Forces confirmed on Friday.

A medical certificate listed pneumonia as the cause of death, the BBC reported. The baby was less than three weeks old when he died Thursday.

Shamima Begum, who was 15 when she and a couple of friends fled to Syria in 2015, had been begging to return to the U.K. prior to her son’s birth, saying she wanted to raise him in Britain.

The young mother has been living in a refugee camp in northern Syria and had told reporters she feared for her newborn’s health. Begum previously had two children who allegedly died due to malnutrition and disease.

But following her third child’s birth last month, British officials stripped the 19-year-old of her citizenship as it is permitted to do in cases where it is “conducive to the public good.”