WASHINGTON - The United States has been using Shamsi airbase in Pakistan's Balochistan province to station unmanned Predator drones that have been used to attack terrorist targets inside the country's tribal areas, an unnamed senior US official told an American television network on Thursday. The confirmation contradicts a stream of previous denials from officials and comes after the Times of London published a Google Earth image apparently showing three US drones at the airbase as early as 2006. The senior US official told Fox News that the US was in fact launching Predator UAV strikes from at least one base in Pakistan, confirming a statement made by US Senate intelligence committee Chairwoman Dianne Feinstein last week. The California Democrat riled intelligence circles when she seemed to reveal sensitive information about such a Pakistan-based staging ground during a hearing. The official said that slip led to the initial denials from other officials that the US was using Pakistani bases. The Times also obtained a copy of the Google Earth image, whose coordinates confirm that it is the Shamsi airfield, also known as Bandari, about 200 miles southwest of Quetta, the report said. US special forces used the airbase during the invasion of Afghanistan in 2001, but the Pakistani government said in 2006 that the Americans had left and both sides have since denied repeatedly that Washington was using Pakistani bases. Monitoring Desk adds: The US and other NATO member countries have had a quiet, unwritten agreement for the past three to five years to allow the CIA to fly unmanned drones out of remote airstrips in the Pakistan-Afghanistan border region, a senior military official from a NATO country confirmed to CBS News on Thursday. In the past week, speculation has mounted over the extent to which Pakistan was aware of such flights, amid evidence that at least some of the drones were being launched from airstrips in remote Pakistani regions. The issue is potentially explosive for Pakistan - a country that has been an ally to the US in Washington's fight against extremism, but has routinely protested the drone strikes on suspected Taliban and Al-Qaeda militants in Pakistan's border region, which have also caused numerous civilian casualties. On Tuesday, The Times newspaper of London reported that the drone flights were originating from an airstrip known as Shamsi in Balochistan. On Thursday, the Islamabad-based NATO military official, who spoke to CBS News on condition of anonymity, said the US, Pakistan and NATO had all collaborated in the use of remote locations in Pakistan and Afghanistan to operate the drones. "There is no single site you can name. We are looking at different locations both in Pakistan and Afghanistan," said the official. "If the Shamsi base has been found to be a home for the drones, that is not the only location." A NATO country diplomat stationed in Islamabad, who also spoke to CBS News on condition of anonymity, confirmed the information given by the military official. "There is no one location. The locations keep on changing in both countries (Pakistan and Afghanistan). But yes, there are drones flying from locations in both these countries," said the diplomat. However, a Pakistani government minister told CBS News on Thursday there was no question of ending Islamabad's support for Washington, especially given Pakistan's weak economy which, has made it rely on the US for badly needed financial aid. "The US holds a vital lifeline for Pakistan. How can we move to cut that off ourselves," asked the minister, who also asked not to be named due to the sensitive nature of the matter.