Indian Ambassador to the UN Savitri Kunadi: India knew Pakistan had weapons capability

But, the news from Pakistan caused uproar in the Indian parliament. The prime minister and Interior Minister Lal Krishna Advani rushed out of the parliamentary chamber when they heard.

The prime minister spoke of the need for "grave, calm and determined" debate and told the house: "I am trying to collect all the facts."

"These tests have created a new situation ... We may have our differences, but if the challenge is from abroad, then that challenge must be met with a united house and a united nation," he said.

Opposition deputies who had been in the middle of a debate on India's five nuclear tests last week rose to their feet at the news of the blasts in neighbouring Pakistan.

The Communist Party of India-Marxist leader Somnath Chatterjee said: "It is a nuclear arms race which you have started in this region."

He demanded to know why Indian intelligence had not had any advanced information about the tests.

Earlier India dismissed Pakistan's fears that it would attack Pakistan's nuclear sites. A foreign ministry statement said the allegations were utterly absurd and malicious.