Sunan Abu Dawud
4766
Sahih+2

The tradition mentioned above has also been transmitted by Anas through a different chain of narrators in a similar manner. This version adds; Their sign is shaving the head and eliminating the hair. If you see them, kill them. Abu Dawud said:Tasmid means uprooting the hair

SahihAl-Albani
SahihMuhammad Muhyi Al-Din Abdul Hamid