Police said the arrested duo confessed that they kept the head of an animal at a shrine in Makdampur locality under Parsudih police station on the intervening night of June 13 and 14.
The two persons, who were arrested yesterday, told his interrogators that they were asked to do it by a person who wanted to avenge his arrest following communal tension here last year, police said.
Another person who allegedly helped the two accused enter and get out of the shrine was detained.