A British doctor has died in Syria after a makeshift hospital in which he was working was shelled, a charity said.
Dr Isa Abdur Rahman, a 26-year-old graduate from Imperial College London, put his medical career on hold so that he could travel to Syria and help treat injured civilians.
Dr Rahman, from London, was in the northwestern city of Idlib, where he was volunteering with the British charity Hand in Hand for Syria (HIHS), when a bomb hit the medical facility where he was working on Wednesday. He died shortly afterwards.
Faddy Sahloul, chairman of HIHS, paid tribute to him, describing him as "one of the bravest and most dedicated people I have met".
Mr Sahloul said: "I was very close to Dr Isa, a shy young man whom I first met two years ago.
"We spent a significant amount of time working together in Turkey and Syria, and he was one of the bravest and most dedicated people I have met.
"Everyone who knew him is shocked and saddened to hear the tragic news of his death, but we can draw comfort from the fact that he died doing work that he loved.
"Our thoughts and prayers are with his wife and family at this difficult time."
Two other civilians are thought to have died and two people were wounded in the attack on Wednesday.
A Just Giving donation page set up by HIHS following his death has already raised more than £25,000.
On Dr Abdur Rahman's Just Giving page, he was described as "inspirational" and "deeply-caring".
The message read: "Those who knew him personally, and those who have heard of him, will know what an amazing, inspirational, kind and deeply-caring person he was.
"It is quite hard to even begin describing what an amazing person he was, and all of us are still in shock."
Mr Sahloul told The Times he hoped that, after last week's attack on a British soldier in London, the story of Dr Abdur Rahman would serve as a reminder of the good that British Muslims were doing in the world.