French citizen Adrien Lionel Kayali, as claimed by the Syrian Democratic Forces, is seen in this undated handout picture released May 24, 2018. Syrian Democratic Forces/Handout via REUTERS ATTENTION EDITORS - THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. NO RESALES. NO ARCHIVES.

BEIRUT (Reuters) - The U.S.-backed Syrian Democratic Forces (SDF) said on Thursday they had arrested a French citizen who headed an Islamic State group in Syria and had been involved in the Paris and Nice attacks in 2015 and 2016.

An SDF statement said the man arrested was Adrien Lionel Kayali and that he was born in 1983 and converted to Islam in 2003. It said Kayali, who also goes by the name of Abu Osama, had been arrested and then released in France in 2010 on suspicion of belonging to terrorist organizations.

French media have reported the captured man’s name as French citizen Adrien Guihal, wanted in connection with terrorist activities in France.

SDF media spokesman Mustafa Bali told Reuters Adrien Lionel Kayali and Adrien Guihal were two names for the same man.

French judicial sources told Reuters on Thursday there is an arrest warrant for an Adrien Guihal from 2015, and that he is suspected of having claimed responsibility for attacks in Nice and Magnanville, near Paris, in France in 2016.

The SDF, a alliance of Kurdish and Arab fighters led by the Kurdish YPG militia, said it believed Kayali had entered Syria in March 2015 into Islamic State-held territory. The SDF said it captured him in the Raqqa region of northern Syria.

The U.S.-backed SDF control much of the territory east of the Euphrates in Syria’s Deir al-Zor province and drove Islamic State militants from their former de facto capital Raqqa in late 2017.