Mohammed Abu Khedair was found dead Wednesday after being abducted from his home in Jerusalem.
His body was badly burned and autopsy results revealed he had been burned to death and struck in the head with a blunt object.
Shin Bet, Israel's domestic security service, arrested six young suspect in the teen's slaying. They were described as Jewish extremists by police sources, the Los Angeles Times reported.
"A number of suspects were arrested for the killing," said police spokesman Micky Rosenfeld. "There are strong indications that the background was nationalistic."
The slaying of Khedair is thought to be in retribution for the abduction and killing of three Israeli teens last week. Khedair's body was found one day after the funerals of Naftali Fraenkel, Eyal Yifrach and Gilad Shaer, who were suspected of being killed by Hamas.