Robin Cook urges Pakistan and India "to engage in dialogue"

Mr Cook said Britain was "dismayed" by Pakistan's decision to proceed despite the warnings of the international community.

"It accentuates our grave concern about the increased risk of nuclear and missile proliferation in South Asia, and of escalating tension in that region," Mr Cook said.

Pakistan is keeping up its military strength to rival India

"We urge Pakistan, along with India and other states in the region, to refrain from further tests and the deployment of nuclear weapons or ballistic missiles."

He called on the two nations "to engage in dialogue which addresses the root causes of the tension between them, and to build confidence, rather than seek confrontation."

The British High Commissioner in Islamabad has been instructed to convey the strong protests of the UK and the EU to the Pakistani government.

Blair involvement

Tony Blair has expressed his "dismay" at the Pakistan nuclear tests. It was revealed he had talked to the country's prime minister on Tuesday in a bid to talk him out of the move.

His spokesman said Mr Blair had told his opposite number that a country's "prestige and standing" was not measured in this way. He also pointed out that Brazil and Argentina had started down the same path but been persuaded to turn back.

Mr Blair did not rule out following America's lead and imposing sanctions on Pakistan - but Britain has not hit India, which tested its own nuclear weapons last week.

The prime minister now wants Pakistan to get into early discussions about signing up to the Comprehensive Test Ban Treaty.

'Regrettable explosions'

The Shadow Foreign Secretary Michael Howard said the explosions were "very much to be regretted".

He added: "Every effort must now be made to ensure that India and Pakistan sign up to the Nuclear Non-proliferation Treaty and the Comprehensive Test Ban Treaty."

The Liberal Democrat foreign affairs spokesman Menzies Campbell said: "Unless there is restraint and common sense the nuclear powder-keg in the Asian sub-continent could easily be ignited."

'Nuclear hypocrisy'

Anti-nuclear groups joined in the condemnation of Pakistan, but also accused Britain and the other established nuclear nations of hypocrisy.

Dave Knight, the chairman of the Campaign for Nuclear Disarmament said: "This crisis has highlighted how untenable the position adopted by the nuclear weapons states for the last 50 years really is.

"Britain and other nuclear weapons states cannot in one breath describe nuclear weapons as 'essential for our security' then in the next breath criticise India and Pakistan - surrounded by potentially hostile neighbours - for developing their own."

Global disarmament was the only real solution, he said.

British Pakistanis support tests

Pakistani Prime Minister Nawaz Sharif: defended the test

However, support for the tests came from Kyoom Chaudry, of the Council of British Pakistanis.

He said Pakistan and India should not engage in a nuclear arms race, but he stressed the need to look at the situation "in realistic terms".

Mr Chaudry said the international community had not delivered a solution to Pakistan's conflict with India, forcing Pakistan to take action - even at the risk of losing international aid.

He added: "In that sort of situation countries like Pakistan have to come out under pressure from their people to show that they can defend themselves.

"They had the choice of two things - one is the security of their country and the other is the aid.