British man Abu Layth al-Khurasani was killed in the past few days fighting for Islamist forces in Syria.
His friends paid tribute to his "martyrdom" on Twitter and Instagram.
He sent his last tweet on January 30th, writing: "Turkey are now actively aiding FSA on the borders of Al Ra'i, there are two Turkish tanks guarding a checkpoint close to the town."
More top news
A one minute silence has been held at the Queen's Garden Party in memory of the 22 people killed and 59 injured in the Manchester attack.
Mancunians have come together in defiance after a suicide bomber killed 22 people at a concert.
Extra armed police will be deployed to Wembley and Twickenham this weekend, police have confirmed.