By Paul Anderson
BBC News, Islamabad
US officials say a new TV and radio campaign to smoke out details of key al-Qaeda suspects who may be hiding in Pakistan has yielded some useful leads.
The adverts ask for information on Bin Laden and 13 other suspects
The adverts highlight financial rewards on offer for information leading to the arrest of any of 14 suspects, starting with Osama Bin Laden.
He is widely believed to be sheltering in the rugged tribal belt on the Afghan-Pakistan border.
US officials would not be more specific about the information received so far.
The 30-second adverts hit Pakistan's television screens this week with an emotive message.
Over pictures of Bin Laden, Ayman al-Zawahiri, his deputy, and Taleban leader Mullah Omar, a voice appeals to viewers: "Who can stop the terrorists? Only you."
Although there is no hard evidence, all are widely believed to be hiding along Pakistan's mountainous and remote border with Afghanistan.
The adverts, however, are being broadcast in Pakistan's four main languages - Urdu, Pashto, Sindhi and Baloch - suggesting that the Americans believe the 14 key al-Qaeda suspects featured could be anywhere in Pakistan.
US officials say they have had more than 25 calls, some of which have yielded what they say is useful information.
They declined to comment on whether any of it focused on Bin Laden.
The financial rewards range from $5m (£2.6m) to $25m (£13.2m) for al-Qaeda's leader and his deputy.
The campaign is part of the US "Rewards for Justice" programme. Since it started, $57m (£30m) has been paid out to more than 40 informants.
Not surprisingly, the Americans initially ran into resistance from the authorities who, because of the deep hatred many Pakistanis feel towards the US, were reluctant for the government to be associated with the campaign.