A 22-year-old man was arrested from Thane district on Sunday, around 12 hours after he allegedly killed a teenage boy and injured another without any provocation, police said.

The accused, Sameer Waghe, confronted the victim Tushar Dede, 18, and his two friends in Barku Pada area of Ambernath on Saturday night while they were having drinks, and attacked them with a knife, a police spokesperson said.