43 years since first nuclear weapon test by India at Pokhran

Indira Gandhi, then Indian prime minister, at Pokhran, the site of India's first underground nuclear test. (Reuters)

On May 18th, 1974, India tested its first fission bomb, a nuclear weapon which had the explosion power similar to the bomb dropped by USA in Hiroshima, Japan. (AFP)

Due to border disputes with China, India in 1968 had refused to sign the Nuclear Non Proliferation Treaty. To counter China and Pakistan's growing threat, India actively sought to develop a nuclear weapon in the 70s. (Photo |Reuters)

The project was kept in utmost secrecy by the Indian government. Indira Gandhi maintained an iron hand over the 'Smiling Buddha' test with even the defense minister learning about the event only after it happened. (Photo|PIB)

The director of Bhabha Atomic Research Centre (BARC), Raja Ramanna was the head of the entire nuclear bomb project. (Dinamani Photo By K Vaidiyanathan)

The bomb was designed by the second in command, Dr P K Iyengar. (Express Photo)

A crater marks the site of the first Indian underground nuclear test conducted 18 May 1974 at Pokhran in the desert state of Rajasthan. (AFP)

The nuclear test by India made it the sixth country, the only one outside the five members of UN Security Council - US, Soviet Union, United Kingdom, France and China to achieve the feat, thereby breaking the nuclear monopoly. (AFP)