Despite its very public withdrawal from Shamsi airfield at the weekend, the United States continues to have access to a number of military airfields inside Pakistan - including at least one from which armed drones are able to operate, the Bureau understands. The first concrete indications have also emerged that the US has now effectively suspended its drone strikes in Pakistan. The Bureaus own data registers no CIA strikes since Nov 17. Islamabad is furious in the wake of a Nato attack which killed 24 Pakistani soldiers on its Afghan borders. As well as suspending Nato supply convoys through Pakistan, anti-aircraft missiles have also reportedly been moved to the border with Afghanistan. Pakistan also demanded that the US withdraw from Shamsi, a major airfield in Balochistan controlled and run by the Americans since late 2001. US Predator and Reaper drones have operated from the isolated airbase for many years. Technically the base is leased to Abu Dhabi in the United Arab Emirates, which allowed Pakistan to deny a US presence for many years. Now the US has quit Shamsi, with large US transporter planes stripping military hardware from the base. But the US will continue to have access to at least five other Pakistani military facilities, according to a Pakistani source with extensive knowledge of US-Pakistani military and intelligence co-operation. US control One of those bases is Shahbaz at Jacobabad, the first home of US surveillance drones in Pakistan. Armed CIA drones have operated there for some years, the source said. It is not yet clear whether, if the US resumes drone strikes, attacks will again be launched from Shahbaz. During lethal heavy flooding in autumn 2010, Pakistans health minister Khusnood Lashari protested publicly that Pakistan could not use Jacobabads airport to deliver food aid. 'Health relief operations are not possible in the flood-affected areas of Jacobabad because the airbase is with the United States, he told parliament. The US denied at the time that it controlled Shahbaz. According to the Bureaus source this is technically correct. The Pakistan Army provides an outer protective layer for the base. But around 50 American military personnel provide an inner security cordon for a US-only area. The Bureaus well-placed source revealed that the US military will continue to have access to at least five military bases in Pakistan. These include: Shahbaz/Jacobabad - original location for US drones inside Pakistan. Armed CIA drones may still operate from here Chaklala - a Pakistan Air Force base near Islamabad with a permanent US military presence. The base handles US logistics and other movements. Around 300 troops were based there during Pakistans 2005 floods, for example Quetta - A Pakistan Air Force base which previously featured heavily in US logistical operations. Although there is now no permanent US presence, the Pentagon is able to make use of the base 'as and when Tarbela - This Pakistan Special Forces base, between Rawalpindi and Peshawar, is described by the source as 'just a big helipad, really. US Chinook helicopters have been stationed here, for example during the 2010 floods Peshawar - a Pakistan Air Force base, the site handles logistics. On occasion US troops have landed transited from here to other locations The US was asked to leave Shamsi as part of a face - saving operation in the wake of Natos deadly attack, the Bureaus source believes: 'Shamsi is the public face of drone strikes in Pakistan, so it had to go. According to reports, Islamabad is trying to negotiate a new settlement with the US which would allow CIA drone strikes to continue 'only on the basis of Pakistani intelligence and a firm assurance that there will be no unilateral military action. Whatever its situation within Pakistan the CIA will also continue to operate from a number of secret bases on the Afghan side of the border, including Forward Operating Base Chapman - the scene in December 2009 of a devastating Taliban counter-attack which killed seven CIA agents involved in the drone campaign. Campaign on hold The Bureaus own data shows no CIA drone strikes in Pakistan since November 17, nine days before Natos 'blunder. There have been similar pauses during other fraught periods, for example during the Raymond Davis case earlier this year. On Monday the Long War Journal reported that the drone campaign is on hold. It cited a US intelligence official as saying: 'There is concern that another hit [by the drones] will push US-Pakistan relations past the point of no return. We dont know how far we can push them [Pakistan], how much more they are willing to tolerate. A second official told LWJ that the US retained the option to strike if 'an extremely high value target pops up. Lt Colonel James Gregory, asenior Pentagon spokesperson, declined to comment on the specifics of the Bureaus report. However, in relation to the Shamsi withdrawal he said: 'Its important to add that the United States and Pakistan have had a long and complicated relationship, but even as we have differed on a number of important issues, our cooperation in the future remains vital to dealing with the common threats we face from terrorism. Bureau of Investigative Journalism