The Atlantic and the National Journal, in a joint report citing unnamed sources, wrote that the US raid that killed Al-Qaeda chief Osama bin Laden in May at his Pakistani compound reinforced Islamabad's longstanding fears that Washington could try to dismantle the country's nuclear arsenal.
As a result, the head of the Strategic Plans Divisions (SPD), which is charged with safeguarding Pakistan's atomic weapons, was ordered to take action to keep the location of nuclear weapons and components hidden from the United States, the report said.
Khalid Kidwai, the retired general who leads the SPD, expanded his agency's efforts to disperse components and sensitive materials to different facilities, it said.
But instead of transporting the nuclear parts in armoured, well-defended convoys, the atomic bombs "capable of destroying entire cities are transported in delivery vans on congested and dangerous roads," according to the report.
The pace of the dispersal movements has increased, raising concerns at the Pentagon, it said. Pakistan has long insisted its nuclear arsenal is safe and the article quotes an unnamed official from the powerful Inter-Services Intelligence agency saying: "Of all things in the world to worry about, the issue you should worry about the least is the safety of our nuclear program."