The attackers who ambushed and killed four U.S. soldiers in Niger had “no real ties” to the Islamic State group, the SITE Intelligence Group said Friday.

The company, which tracks terror groups, said the leader of the jihadist extremists in West Africa, Adnan Abu Waleed al-Sahrawi, had pledged allegiance to ISIS in 2015 but never followed through with any coordination, which may explain why ISIS has not claimed responsibility for the attack.