WASHINGTON — Police in Fairfax County have arrested two more teens who they say beat a man in Annandale, Virginia, and then set his backpack on fire over the weekend.

The two teens are both 15. One was arrested Monday night and the other was arrested Tuesday morning, Fairfax County police said in a news release.

Police previously arrested a 14-year-old, who they said took part in the attack, as he fled the 4500 block of Commons Drive Sunday afternoon.

Police said they believe they have now arrested all the suspects involved in the attack on the man, who has only been identified as a 47-year-old Fairfax County resident.

All three teens face attempted robbery and malicious wounding charges.

Police said the man was initially sleeping when the teens set fire to his backpack. The man, who had burns on his clothing and his backpack, was treated at a hospital Sunday night and released.

Police have said they believe the teens were trying to rob the man’s backpack and were attempting to burn the straps off the backpack in order to steal it. Police said on Tuesday they do not believe the incident is gang-related.