More tests by Pak likely, says US

Pakistan Foreign Minister Gohar Ayub Khan said in interviews to at least two television networks that more tests cannot be ruled out. quot;The Prime Minister has not said anything in his speech about more tests8230; I cannot say anything8230; We cannot rule out anything,quot; he variously said.

But Pakistan8217;s five-for-five nuclear tests are not all they are bruited to be, US experts said, downgrading both the number and strength of the devices Islamabad claims to have exploded.

According to preliminary estimates, Pakistan had exploded as few as two nuclear devices, both in the range of 5 to 10 kilotons, US intelligence were quoted astelling various American media. The atomic bomb that destroyed Hiroshima in 1945 was a 12-kiloton weapon.

Unnamed officials were quoted as saying Prime Minister Nawaz Sharif8217;s announcements that Pakistan had conducted quot;five successful nuclear explosions,quot; levelling the score with India, was probably political propaganda intended for domestic consumption. The officials also discounted the possibility of Pakistan having armed its medium range Ghauri missile and the bogey of an imminent Indian attack, saying both were aimed at the domestic audience.

Meanwhile, the US Geological Survey in Golden, Colorado, said Pakistan8217;s strongest test had a preliminary magnitude of 4.9 on the Richter scale compared to India8217;s strongest blast, which registered 5.4 and, according to some US experts, had a tonnage of between 25,000 and 30,000.

Seismologists also recorded a single signature. The Incorporated Research Institutions for Seismology, a scientific group in Washington, said instruments at its station in Pakistanrecorded the blast as having a magnitude of 4.8, equal to between 8,000 and 15,000 tons of high explosive.That would make its size about half to a third of the Indian device. New Delhi announced that it has tested a thermonuclear device, better known as a Hydrogen bomb, and also called a city-buster. Data from the Pakistani blast suggested it was the right size for a warhead for a medium-range missile, according to IRIS seismologist Dr Terry Wallace.

Experts are surprised by the Pakistani claims about the size and number of the devices, and are suggesting that Islamabad is either fibbing about the number of tests or has fudged production of fissile material in the past.

There was also considerable surprise over Islamabad8217;s claim that it had already fitted its medium range Ghauri missile with nuclear warheads. India has not claimed, or known to have, fitted its Prithvi missile, let alone the longer range Agni missile, with nuclear warheads.

quot;If the Pakistani official announcement that they are matingwarheads with missiles is true, they have crossed an important threshold. The Indians don8217;t have a match,quot; Michael Krepon, an arms control expert who heads the Stimson Center in Washington said.

But other experts were more leery saying fitting missiles with warheads was still beyond Pakistani reach despite considerable Chinese help in the matter. quot;The Pakistanis have a small, efficient lightweight device. The chances it could be fitted to a missile is very good. But it would probably take them a year to do that,quot; said Gary Milhollin, who heads the Wisconsin Project, a proliferation think tank.