Two youths were arrested on Wednesday for allegedly attempting to stab a police head constable with a dagger in Srikalahasti police limits on Tuesday. His accomplice, Achi Srinivasulu (22), allegedly took out a dagger from his pocket and attempted to stab the head constable. The dagger allegedly used in the attack was also seized from Srinivasulu. The police said Srinivasulu was a habitual offender and had cases pending against him at the Srikalahasti II Town police station. The police also found that Jithendra Kumar, who allegedly accompanied Srinivasulu during the attack, is a third-year B.Tech student.