<P> Pokhran - II consisted of five detonations , the first of which was a fusion bomb while the remaining four were fission bombs . The tests were initiated on 11 May 1998 , under the assigned code name Operation Shakti , with the detonation of one fusion and two fission bombs . On 13 May 1998 , two additional fission devices were detonated , and the Indian government led by Prime Minister Atal Bihari Vajpayee shortly convened a press conference to declare India a full - fledged nuclear state . The tests resulted in a variety of sanctions against India by a number of major states , including Japan and the United States . </P>
who was india 's prime minister when its first nuclear test were conducted
Atal Bihari Vajpayee