Pakistani authorities said on Tuesday they didn't know whether their ambassador to Afghanistan had been kidnapped, a day after he went missing in a Pakistani tribal region plagued by bandits and militants.

Ambassador Tariq Azizuddin was on his way to Kabul from the northwestern Pakistani city of Peshawar when he disappeared along with his driver and bodyguard in the Khyber tribal region.

'The search is on. We have nothing to share at the stage,' Foreign Office spokesman, Muhammad Sadiq, told Reuters. He refused to speculate whether the envoy had been kidnapped.

'We don't know what happened, we have no idea,' Sadiq said. 'There is no confirmation he has been kidnapped.'

A security official said the envoy was to change cars at the border but he did not show up and was believed to have not reached the border.

Afghanistan's President Hamid Karzai was sure the envoy had been snatched.    'The Pakistan ambassador to Afghanistan has been kidnapped while travelling to Afghanistan,' Karzai said in Kabul, during a conference on education.    'I hope he is safe and I hope he will be released soon.'

The historic Khyber Pass is the main road link to landlocked Afghanistan in northwestern Pakistan. Khyber is notorious for smugglers and bandits, but unlike other parts of the tribal belt on the Afghan border it has been relatively free of the violence linked to Al Qaeda and the Taliban, though militant activity has picked up in adjoining regions.

Scores of people were killed late last year in clashes between tribal militants loyal to two rival clerics in Khyber.

Four Pakistani workers of the International Committee of the Red Cross went missing in the same region earlier this month. They have not been found.

Meanwhile, two technicians from the Pakistan Atomic Energy Commission were kidnapped on Monday near the northwestern town of Dera Isamil Khan, police said.

'The technicians were going for some geological survey in the area when they were kidnapped at gunpoint along with their driver amd five local people,' Romail Akram, a senior police official in the area said.

'The local people have been released but the technicians and their driver are still missing. We don't have any idea, so far, who has done it.' The security situation in Pakistan has deteriorated markedly since mid-2007, mainly in the northwest, with militants linked to the Taliban and Al Qaeda carrying out a suicide bomb campaign against security forces and politicians campaigning for an election on Feb.18.

More than 400 people have been killed in militant related violence since the beginning of this year alone.-Reuters