Even while the Tor was being introduced into service, work started on improving the system, resulting in an enhanced version, the Tor-M1. Many improvements over the original system were made; these included the addition of a second fire control channel, allowing two targets to be engaged at once; as well as upgrades to the optical tracking system and computer equipment. ECM protection and warhead design were also modified, as was the ammunition handling system. State tests, conducted between March and December 1989, showed that the result was a system which could engage more targets in a shorter time frame with reaction times reduced by over a second and an increased probability of target destruction. Further modifications occurred partly as a response of insight gained from the 1995 NATO bombing in Bosnia and Herzegovina resulting in the Tor-M1-1, or Tor-M1V, which offered improved network connectivity and ECM functions as well as protection against countermeasures.