The newborn son of Shamima Begum has died in a Syrian refugee camp. Jarrah was buried on Friday, three weeks after the east London teenager who joined Islamic State gave birth.

A Kurdish intelligence official said the infant had been taken to hospital in al-Roj camp in north-eastern Syria with breathing difficulties several times in the past week. A friend of Begum said “the baby turned blue and was cold” before being rushed to a clinic inside the camp. Jarrah is understood to have been buried along with two other children who were burned in a fire on Thursday night.

The death was confirmed on Friday by Begum’s family lawyer, Tasnime Akunjee. It will raise fresh questions about conditions in north Syrian camps, and put protection obligations for some of the world’s most vulnerable children in the spotlight.

Shamima Begum’s case shows us citizenship can never protect our rights | James Bridle Read more

Begum, 19, has been told by the home secretary, Sajid Javid, that she will be stripped of her citizenship after fleeing the UK to join Isis, and reaffirming her commitment to the terrorist group after surrendering to Kurdish forces in eastern Syria. Such a move would leave her stateless, and has been criticised by child welfare advocates, who have said that children of foreign nationals remain dangerously exposed to life-threatening conditions while in detention.

Following news of the boy’s death, the shadow home secretary, Diane Abbott, also criticised Javid’s decision. She tweeted: “It is against international law to make someone stateless, and now an innocent child has died as a result of a British woman being stripped of her citizenship. This is callous and inhumane.”

Begum was 15 when she travelled with two other schoolgirls to join the terror group in February 2015. She married the Dutch national Yago Riedijk, 27, soon after arriving in Syria. All three of their children are now confirmed to have died.

The heavily pregnant Begum spoke last month of her desire to return to the UK as the self-styled caliphate collapsed. Originally held in al-Hawl camp in northern Syria, she was transferred to al-Roj a week ago.

Play Video 2:44 UK citizenship decision is heartbreaking, says Shamima Begum – video

The human rights lawyer Clive Stafford Smith said: “It is very sad to hear that Shamima Begum has just watched her third child die in just a few months. While she has made some very stupid decisions, and nobody is saying otherwise, she is still a teenager.

“It is also sad to see Sajid Javid trying to better his chances of becoming prime minister by illegally stripping her of her passport, rather than maturely focusing on the needs of a helpless infant who might have been rescued. Indeed, it is just this kind of ill-considered populism that is further alienating many Muslims when we should be proving that we really do believe in human rights for all.”

Shelina Janmohamed, an author and commentator on British Islam and Muslim women, said: “This was an innocent baby caught up in the middle of a horrendous situation, and the only response as a human being that you can have to that is to feel deep despair that a baby was lost. The child was a British citizen and the British government had a duty to the child, and we failed him. It is a human tragedy.”

Richard Barrett, the former director of global counter-terrorism at MI6, said he had sympathy with Begum as a new mother who had lost her third child, but he did not feel the British government would change its stance.

“It must be devastating. However, I can’t imagine it will make any difference to the Home Office’s attitude towards her, nor towards the people who thought she should be allowed to come back in.

“It would have been difficult to bring the child back without its mother. I’m not sure that would have been right – to separate such a young child from its mother. I don’t think this will change the government’s opinion of its action.”

Speaking before news of the baby’s death had been confirmed, Javid told the BBC: “Obviously, I don’t know whether that news is true or not, but what I will say, sadly, [is that] there are probably many children, obviously perfectly innocent, who have been born in this war zone.

“I have nothing but sympathy for the children that have been dragged into this. This is a reminder of why it is so, so dangerous for anyone to be in this war zone.”

Following confirmation of the death on Friday night, a government spokesman said: “The death of any child is tragic and deeply distressing for the family. The Foreign and Commonwealth Office has consistently advised against travel to Syria since April 2011. The government will continue to do whatever we can to prevent people from being drawn into terrorism and travelling to dangerous conflict zones.”

The Conservative party chairman, Brandon Lewis, defended Javid’s decision to strip Begum of her British citizenship.

Speaking on BBC Radio 4’s Today programme, he said: “The loss of any life of any child is absolutely tragic and is a very clear reminder – this whole case – of the danger of travelling out to that area and getting involved.

“The home secretary will have had advice and I know he made a decision based on what is in the national interest and the security of people here in the UK. There is no question that the duty of a home secretary in this country is to keep British people safe.

“Inside Syria, whether in a camp or maybe somewhere else, there is no British consular presence.”

Hundreds of children born to foreign nationals remain in Syrian camps, where women and children who left territory held by Isis have been transferred by Kurdish forces. Many governments have not yet formalised a position on how to deal with nationals who left to join Isis over the past five years. France has said it will repatriate 130 children, but is less willing to allow their parents to return. The UK has not yet finalised a policy, but some citizens have been allowed to re-enter.

The International Rescue Committee said the number of infant deaths in al-Hawl reached 100 on Friday, a milestone that occurred as reports persistently said conditions in the camp were worsening. The camp’s population had already swollen to breaking point before another 12,000 people arrived over 48 hours. The latest groups have come from the town of Baghuz, the last refuge of Isis, which has been under intensive attack by the Kurdish forces surrounding it.

Misty Buswell, the International Rescue Committee’s Middle East advocacy director, said: “The IRC and other agencies are doing all they can to help the new arrivals, but al-Hawl camp is now at breaking point. No one could have guessed that such a large number of women and children were still living in Baghuz.

“There is now an urgent need for thousands more family tents to get to Hawl to help shelter the latest arrivals, as well as increased funding to support the health crisis unfolding at the camp.”

The IRC said at least 100 people, overwhelmingly children, have died en route to the camp or soon after arriving. Two thirds of the deaths were babies and infants under five years old, it claimed.

“[This is] due to a combination of malnutrition and hypothermia,” said Buswell. “Unfortunately, this figure could be the tip of the iceberg, as we’ve been told some children also died as people crossed the desert to escape Baghuz and were buried before they even began the journey.”