The chorus of international condemnation, which began immediately after India announced renewal of nuclear testing on Monday, with strong statements from the US, Pakistan, Japan, New Zealand and Australia, continued throughout yesterday.
One of the most significant new comments came from China, which expressed "grave concern". State radio quoted the foreign ministry spokesman Mr Zhu Bangzao as saying the tests "run against international trends and are disadvantageous to the peace and stability in South Asia".
China took 24 hours to react officially, and was the last of the five recognised nuclear powers to issue a statement.
The Russian Foreign Minister, Mr Yevgeny Primakov, also criticised India but said Moscow was unlikely to back any sanctions against New Delhi.
The father of Pakistan's nuclear research programme meanwhile said that a bomb could be assembled within a week and he was waiting only for the order to carry out a nuclear test. "We are like a cook waiting for the orders," Mr Abdul Qadeer Khan declared.
A senior official at the United Nations permanent Conference on Disarmament in Geneva said efforts would have to be stepped up after India's action. "These three tests clearly emphasise the necessity of additional efforts in the framework of the Conference on Disarmament aimed at maintaining continuity in the disarmament negotiations," said Mr Vladimir Petrovsky, the organisation's secretary-general.
Malaysia, Korea and Thailand also condemned the tests, while Indonesia expressed its concern.
The European Union also expressed dismay. The G-8 group of industrial nations is to discuss how to respond during a weekend meeting in Britain.
France, which has itself faced world criticism over nuclear tests, urged Delhi to join a test ban but stopped short of protesting.
India yesterday found an ally among Tibetans who say their homeland has been turned into a Chinese military camp. The Tibetan Youth Congress, which has 10,000 members in India and tens of thousands of supporters in Tibet, said it would like to congratulate India's Hindu nationalist-led government on the tests.
Sweden will raise the issue in the UN Security Council, Swedish diplomats said. The diplomats said that depending on reactions from the 14 other Security Council members, the Council may decide to react formally to the Indian tests.
Western diplomats said that the Security Council has asked to be briefed on the Indian tests by UN secretariat officials.
The UN Secretary-General, Mr Kofi Annan, speaking in Paris, said: "We had hoped that India would respect the spirit (of the Comprehensive Nuclear Test Ban Treaty) and we were disappointed."
In Bonn, the German government, which has condemned the testing, cancelled a negotiating session scheduled for yesterday with India about development aid.