The first victim was gunned down in Edmonton, north London, on Tuesday, while the other was attacked early on Wednesday in Hounslow, west London.
Detectives have made one arrest in the Hounslow murder investigation. A BBC analysis of homicides in London showed this year eight out of a total of ten fatal shootings had happened since June.
On Tuesday night at about 21:00 BST police were called to Beaconsfiled Road, Edmonton, where they found a man in his 20s suffering from a gunshot wound. He was treated by paramedics but was pronounced dead shortly before 22:00. The Met Police said no arrests have been made over the Edmonton killing.
A few hours later at 02:47 another man was found injured – this time in Clements Court, Hounslow. Detectives said the victim, aged in his early 30s, had suffered stab injuries and was also pronounced dead at the scene. Police homicide statistics in London obtained and analysed by the BBC show there have been more than 75 murder investigations launched in London this year. Ten of these killings have been shootings.