In the first incident, which took place in outer Delhi's Kanjhawla area around 9.30 PM yesterday, Ram Gopal (25) was killed, and his brother-in-law Hariom (27) was injured, when the motorcycle they were riding hit an electric pole, police said.
Hariom is undergoing treatment at a hospital, they said.
The duo worked as labourers and were returning home when the accident took place.
The second incident was reported from northwest Delhi's Rani Bagh area where 26-year-old Pinkesh was mowed down by a vehicle while he was driving his motorbike last night, police said.
One of them, identified as Mulayam Singh was killed while the other Hansraj is currently undergoing treatment at a hospital, they added.
Accused truck driver Jabbar Singh (41) has been arrested, they said.