089320

Since 2016 the IceCube collaboration is distributing alerts of high-energy neutrino detections in order to allow follow-up searches for possible counterparts. Finding them would provide important clues on the origin of the high-energy neutrinos and on the nature of the high-energy cosmic ray accelerators. We ask for pointed ToO observation of the High Energy Starting Events and Extremely High Energy neutrinos detected by IceCube and reported in GCNs. We will employ the best available knowledge of the INTEGRAL instruments to hunt for a possible hard X-ray and gamma-ray counterparts. In absence of a detection we will set the most stringent upper limits. We intend to promptly communicate the results of our ToOs to the general community thus supporting additional multiwavelength follow-ups. [truncated! Please see actual data for full text]