In the first incident, a 12-year-old boy was found beaten to death at his house at Jafarabad area in east Delhi late Sunday night.
"Sarfaraz was spotted in a pool of blood by his elder brother when he returned back to home," a police officer said.
Police said the assailant seemed to be known as the entry into the house was not forced. They are investigating the case from all possible angles.
In the second incident, a 34-year-old mosque's manager was stabbed to death by a neighbour at his house at Mansarovar Park area in east Delhi. The accused Israil, 55, has been arrested.
"Mohammad Ibrahim was attacked with knife and rods by five men while was standing outside the garage of his house," said a police officer.
He was taken to a hospital where doctors pronounced him dead.
Police said the murder seemed the outcome of a personal enmity.
