In the first incident, Surendra Sharma was killed when a motorcyclist rammed into his cycle in Okhla Phase-1 last night.
Sharma died on the spot, police said, adding that the motorcyclist, Jaswant Singh, was arrested.
In another incident, a motorcyclist died when a truck hit him late last night in New Friends Colony area.
The victim was identified as Dhruv Soni, a resident of Sarita Vihar.
The truck driver, Vijay Yadav, has been arrested, police said.