THE HAGUE - A small chain of Pacific islands - some of which were once vapourised by atomic bomb tests - sought in court on Monday to force India, the world's second-most populous country, to get on board with nuclear disarmament.

The tiny republic of the Marshall Islands, which has a population of less than 70,000 people, says that the world's nine nuclear weapons states have violated various obligation to negotiate in good faith to dismantle their nuclear arsenals.

Three of them - India, Pakistan and Britain - are bound by previous commitments to respond to cases brought at the International Court of Justice. India was the first to be heard, on Monday, followed during the week by Pakistan and Britain. They say the claim is beyond the jurisdiction of the court in The Hague

Nobody expects the Marshall Islands to force the three powers to disarm, but the archipelago's dogged campaign highlights the growing scope for political minnows to get a hearing through global tribunals.

The island republic, a US protectorate until 1986, was the site of 67 nuclear tests by 1958, the health impacts of which linger to this day. "Several islands in my country were vapourised and others are estimated to remain uninhabitable for thousands of years," said Marshallese minister Tony deBrum, describing seeing the sky "aflame" from a test 200 miles distant as a nine-year-old boy.

"Many died, suffered birth defects never before seen and battled cancer from the contamination," he added.

The other nuclear powers - including declared powers China, France, Russia and the United States and undeclared nuclear states Israel and North Korea have not responded to the suit the islands filed last year.

The islands say the declared states are bound to negotiate disarmament by the 1970 Nuclear Non-Proliferation Treaty, while the other states face similar obligations under customary international law.

"It is a shame that the other six nuclear armed states have decided that for them there was no need to respond," said Phon van den Biesen, lawyer for the Marshall Islands. "Once the threshold to the use of nuclear weapons is crossed, the law will be a joke and justice will be just a relic of the past."

The Marshall Islands Monday painted a vivid picture of the horrors of nuclear war decades after some of its atolls were vaporised in atomic tests, in an unusual legal battle against the nuclear arms race.

Judges at the International Court of Justice are holding a series of hearings over several days to decide whether it is indeed competent to hear the lawsuits brought against India and Pakistan.

A third hearing against Britain, scheduled to start on Wednesday, will be devoted to "preliminary objections" raised by London.

The Marshall Islands aims to shine a new spotlight on the global nuclear threat, its lawyers said Monday.

Following US-led tests in the 1950s "several islands in my country were vaporised and others are estimated to remain uninhabitable for thousands of years," the country's representative Tony deBrum told the court.

He remembered in particular the "Castle Bravo" test of March 1, 1954, which he witnessed as a nine-year-old while fishing with his grandfather in an atoll, some 200 kilometres (125 miles) from the blast's epicentre.

"The entire sky turned blood red," deBrum recalled when US scientists exploded a hydrogen bomb, with a force 1,000 times stronger than the device dropped on Hiroshima in 1945. "Many died, or suffered birth defects never before seen and cancers as a result of contamination."

The Marshall Islands alleges that despite their suffering, the world's nuclear powers have failed in their obligations under the nuclear Non-Proliferation Treaty (NPT).

They were "not fulfilling their obligations with respect to the cessation of the nuclear arms race at an early date and to nuclear disarmament."

The hearings are starting just days after North Korean leader Kim Jong-Un Friday ordered the country's nuclear arsenal to be readied for pre-emptive use at any time.

The Marshall Islands had sought to bring a case against nine countries: Britain, China, France, India, Israel, North Korea, Pakistan, Russia, and the United States.

India and Pakistan along with North Korea have not signed the NPT treaty, and Israel has never admitted to having nuclear weapons. But the ICJ has only admitted three cases against Britain, India and Pakistan because they already recognised the ICJ's authority.

The six other countries, including the world's two largest nuclear powers the United States and Russia "decided there was no need for them to respond to the Marshall Islands' filing," Majuro's lawyers lamented.

In 1996, the ICJ in another case issued a non-binding advisory opinion in which it urged the world's nuclear powers to negotiate a reduction of their nuclear stockpiles.

But two decades later, very little progress has been made to reduce the nuclear threat, observers attending the case told AFP.

The Marshall Islands therefore decided to sue the world's nuclear heavyweights as "it has a particular awareness of the dire consequences of nuclear weapons," it said in court papers.

Between 1946 and 1958 the United States conducted 67 nuclear tests in the Marshall Islands including Bikini atoll, deBrum told the ICJ's judges.