NEW DELHI: Prime Minister Atal Behari Vajpayee has written separate but identical letters to heads of the G-8 nations to explain the circumstances which impelled India to conduct the three underground nuclear tests on Monday.

The G-8 nations, which are slated to meet in Britain later this week, include the United States, Canada France, Germany, Italy, the United Kingdom, Japan and Russia.

The personal letters from the Prime Minister are part of a massive diplomatic offensive being launched by India to contain any possible damage, which may arise from this fresh development.

According to sources in the Prime Minister's Office (PMO), the detailed note read out by principal secretary Brijesh Mishra at a late night briefing on Monday, explaining India's position, was appended to Mr Vajpayee's letter.

Later, Mr Vajpayee carried out a comprehensive defence review when he took the unprecedented step of attending defence minister Fernandes' weekly meeting at the latter's South Block office here on Tuesday.

The high-level meeting, which lasted about 45 minutes, was attended by the three service chiefs, defence research and development organisation (DRDO) chief APJ Abdul Kalam, the cabinet secretary, the foreign secretary, the defence secretary and thc Prime Minister's Principal Secretary. There were no details forthcoming about the meeting. Sources, however, said that the three service chiefs had been informed in advance about the decision to explode the three nuclear devices.

Mr Fernandes said that nuclear weapons alone could not ensure a nation's freedom and security of its frontiers. Nor could the armed forces by themselves