Nagorno-Karabakh conflict, when Armenian militias were formed to combat Azerbaijani units in Artsakh. On 20 September 1990, the first military unit was created, the Yerevan Special Regiment, with the first oath being held in the Republican Assembly Point and was attended by the first President of Armenia Levon Ter-Petrosyan, Prime Minister Vazgen Manukyan, and defence minister Vazgen Sargsyan. Five battalions were also formed in Ararat, Goris, Vardenis, Ijan and Meghri. In 1991, by the decision of the government, the State Committee of Defense under the Council of Ministers, which facilitated the task of coordinating the defense operations of Armenia, becoming the basis on which the Ministry of Defense was to be established later on. Post-1992 Armenia established a Ministry of Defence on 28 January 1992. The first military unit of the defence ministry to be formed was the 1st Airborne Regiment, where the first Armenian soldier took the oath to the nation that March. Since a significant part of the officers of the Armed Forces were fighters of the self-defense volunteer detachments, a center for raising the qualification of officers was established for their qualification and training, which during its activity it provided about 1,500 officer-graduates. The School of Non-Commissioned Officers produced about 1,000 graduates. The Treaty on Conventional Armed Forces in Europe was ratified by the Armenian parliament in July 1992. The treaty establishes comprehensive limits on key categories of military equipment, such as tanks, artillery, armored combat vehicles, combat aircraft, and combat helicopters, and provides for the destruction of weaponry in excess of those limits. Armenian officials have consistently expressed determination to comply with its provisions and thus Armenia has provided data on armaments as required under the CFE Treaty. Despite this, Azerbaijan accuses Armenia of diverting a large part of its military forces to Nagorno-Karabakh and thus circumventing these international regulations. In March 1993, Armenia signed the multilateral Chemical Weapons Convention, which calls for the eventual elimination of chemical weapons. Armenia acceded to the nuclear Non-Proliferation Treaty as a non-nuclear weapons state in July 1993. In addition to the branches of services listed above, Armenia established its own Internal Troops from the former Soviet Interior Troops after the dissolution of the Soviet Union. Up until December 2002, Armenia maintained a Ministry of Internal Affairs, but along with the Ministry of National Security, it was reorganized as a non-ministerial institution. The two organizations became the Police of Armenia