Pakistan on Saturday said it has increased security for its nuclear arsenal and installations over the past six months though there are no specific threats of plots or conspiracies to take over the atomic weapons.

The country's institutionalised command and control systems includes 10,000 soldiers who are guarding storage and production facilities for nuclear weapons, said Lt Gen (retired) Khalid Kidwai, the chief of the Strategic Plans Division that is responsible for the security and development of the arsenal.

Asked if the government had increased the security for the weapons in the past six months, Kidwai said the state of alertness has gone up.

At the same time, he made it clear that the SPD's intelligence had uncovered no plots or conspiracies to gain control of the nuclear weapons or to make a dirty bomb containing radioactive material.

In a rare briefing for the international media at Chaklala garrison near Rawalpindi, Kidwai said, "There is no conceivable scenario, political or violent, in which Pakistan will fall to the extremist of the Al Qaida or the Taliban type."

The briefing came a day after Pakistan army chief Gen Ashfaq Parvez Kayani dismissed concerns about the safety of the nuclear weapons as unrealistic and based on a lack of understanding of Pakistan's command and control mechanisms.

Noting that the armed forces are always responding to threats, Kidwai said that the SPD and military had planned for all contingencies, including militant threats and any attempt by foreign forces to secure Pakistan's nuclear arsenal.

Referring to Pakistani Taliban commander Baitullah Mehsud, against whom the army is conducting a major operation in South Waziristan, Kidwai said the militant leader has a capability and we are prepared for it.

He made it clear that it would be a disaster for any intruder to attempt to seize the atomic weapons and this would not be do-able.

"We are conscious of the threat... and military planners should always prepare for the worst contingencies," he said.

Kidwai emphasised that atomic bombs were weapons of the last resort and could hypothetically be used in hostilities with a country like India in the event of space losses, severe force destruction or economic losses.

"I hope it never comes to that," he added.

Explaining the robustness of Pakistan's command and control system, Kidwai said adequate safeguards were built into the weapons and delivery systems to prevent their accidental or unauthorised use.

He said a military jet could be over the target, but the codes for arming the nuclear weapon could be held back till the last minute by the National Command Authority, a body headed by President Pervez Musharraf [Images].

It was the third in a series of briefing by Kidwai who had earlier briefed foreign diplomats and attach�s based in Islamabad.