An internal combustion engine with at least two rotatable bodies each defining at least one combustion chamber of variable volume and, for each rotatable body: a pilot subchamber, a pilot fuel injector having a tip in communication with the pilot subchamber, an ignition element positioned to ignite fuel within the pilot subchamber, and a main fuel injector spaced apart from the pilot fuel injector. The engine includes a common first fuel conduit in fluid communication with each main fuel injector, and a common second fuel conduit in fluid communication with each pilot fuel injector. First and second pressure regulating mechanisms which are settable at different pressure values from one another respectively regulate a fuel pressure in the first and second conduits. A method of combusting fuel in an internal combustion engine is also provided.