Washington, Oct 8 : The U. S. drones which were used to kill American-born Islamic cleric Anwar al-Awlaki and other Al Qaeda chiefs have reportedly been infected by a computer virus that logs their every move.

The unmanned Predator, which killed the Yemen-based terror attack planner, and the Reaper crafts are still able to complete missions over Yemen, Afghanistan and other warzones. But each keystroke made by pilots, who operate the drones remotely from a base in Nevada, is said to be recorded by the virus and experts are struggling to remove it, the Daily Mail reports.

Specialists think the infection has hit both classified and unclassified machines at the base, which could prove to be dangerous because some of the data captured by the virus may have been transmitted to the internet and could be available to terrorists online.

In recent years the U. S. military has increasingly relied on drones to target terrorists.

Although, each drone costs between ten million dollars for a Predator and 30 million dollars for a Reaper, they are highly valued because they do not risk the lives of U. S. servicemen.

Their use, particularly in remote areas of Afghanistan, Pakistan and Yemen has risen amid the increasing military death toll. (ANI)