Two employees of Pakistan's atomic energy agency have been abducted in the country's restive north-western region abutting the Afghan border, police say.

Special forces on standby over nuclear threat
"US special forces snatch squads are on standby to seize or disable Pakistan's nuclear arsenal in the event of a collapse of government authority or the outbreak of civil war following the assassination of Benazir Bhutto.

The troops, augmented by volunteer scientists from America's Nuclear Emergency Search Team organisation, are under orders to take control of an estimated 60 warheads dispersed around six to 10 high-security Pakistani military bases.

ISLAMABAD, Pakistan (CNN) -- Pakistani authorities have launched a search operation in the country's tribal region for Pakistan's ambassador to Afghanistan, interior ministry spokesman said Tuesday.

"All law enforcement agencies in Khyber are carrying out search operations and we hope to recover him soon," Javed Iqbal Cheema said.

Pakistani authorities were searching tonight for their country's Ambassador to Afghanistan and two nuclear officials who appear to have been kidnapped separately in the tribal areas of northwestern Pakistan.

Police were also interrogating Mullah Mansour Dadullah, a top Taleban commander who was captured in the northwest yesterday, amid reports that Islamist militants had offered to swap him for the Ambassador.

The envoy is one of the most senior government officials to have been kidnapped in Pakistan's tribal areas.