The present invention provides an internal combustion engine. The present invention relates to an internal combustion engine (100) comprising a first set of cylinders comprising: a first two-stroke compression cylinder (102) housing a first compression piston (122) connected to a first crank shaft (150); an intermediate two-stroke compression cylinder (104) housing an intermediate compression piston (124), wherein said second two-stroke compression cylinder (104) is configured to receive compressed gas from said first two-stroke compression cylinder (102); and a first four-stroke combustion cylinder (108) housing a first combustion piston (128), wherein said first four-stroke combustion cylinder (108) is configured to receive compressed gas from said intermediate two-stroke compression cylinder (104); wherein the internal combustion engine further comprises a second set of cylinders comprising: a second two-stroke compression cylinder (106) housing a second compression piston (126) connected to said first crank shaft (150), wherein said second two-stroke compression cylinder (106) is configured to provide compressed gas to said intermediate two-stroke compression cylinder (104); and a second four-stroke combustion cylinder (110) housing a second combustion piston (130), wherein said second four-stroke combustion cylinder (110) is configured to receive compressed gas from said intermediate two-stroke compression cylinder (104); wherein each one of said intermediate compression piston (124) and said first (128) and second (130) combustion pistons are connected to a second crank shaft (154), said second crank shaft (154) being configured to rotate with a speed of at least twice the speed of said first crank shaft (150).