Superintendent of Police R L Verma said that on Friday a letter, purportedly on the letter-head of Hijb-ul-Mujahideen was received at the district judge office, threatening to blow up the residence and office of the additional district judge.
He said that after receiving the letter, the entire court premises and the judge's residence was searched, but nothing was found.
Verma said that during the investigation name of one Vinod (25) cropped up, who was arrested yesterday.
He said that a case has been lodged against Vinod and Shyamlal, who would be taken on remand.