The ISIS group said the killing of US Pentagon personnel in Syria's ancient city of Palmyra was a "blow" to US forces and Syrian armed factions opposed to it, in its first public comment on the incident.
Two US Army soldiers and a civilian interpreter were killed on Saturday when an attacker targeted a convoy of American and Syrian forces in Palmyra before being shot dead, the US military said. Three US soldiers were wounded.
In an article published on its Telegram channel on Thursday, ISIS accused the United States and its Syrian-based allies of forming a single front against it. It used religious language to frame the assault as a decisive moment intended to dispel doubt among its supporters, but did not explicitly claim responsibility.
US President Donald Trump called the incident "terrible" and vowed retaliation.
Syria's Interior Ministry said on Sunday it had arrested five people suspected of links to the shooting, describing the attacker as a member of the Syrian security forces suspected of sympathizing with ISIS.
The ministry said security units in Palmyra carried out the arrests in coordination with international coalition forces.
Syria has been cooperating with a US-led coalition against ISIS. The United States has troops stationed in northeastern Syria as part of a decade-long campaign against the group, which controlled large parts of Syria and Iraq from 2014 to 2019.
