We present high-sensitivity, high-resolution images of the Ultraluminous Infrared Galaxies (ULIRG; L$_{mathrm{FIR}} > 10^{12}$ L$_odot$) IRAS 23365+3604 and IRAS 07251-0248, taken with the EVN at 6 and 18 cm. The images show a large number of compact
components, whose luminosities are typical of Type IIL and Type IIn Radio Supernovae (RSNe). Further observations of these ULIRGs will allow us to confirm, or to rule out, their nature. The present observations are part of a project that should result in a significant number of SN detections, providing a direct measurement of the Core Collapse Superova (CCSN) rate and allowing us to estimate the Star Formation Rate (SFR) in our sample of ULIRGs .
