The controversial drone programme run by the Central Intelligence Agency (CIA) in Pakistan is believed to be winding down.

The targeted killings of Islamist militants have been one of the contentious factors in the relationship between Islamabad and Washington for the past several years.

The number of drone attacks has come down gradually and there have been no bombings by unmanned aerial vehicles since last December. This is attributed to several factors including diplomatic lobbying and change in tactics by militant outfits.

"The programme (in Pakistan) appears to have ended," Peter Bergen of the Washington-based think tank, New America Foundation, told the Associated Press.

During his latest major foreign policy address, President Barack Obama referred to drone strikes but did not directly mention Pakistan. He only cited Yemen and Somalia when he said Washington would push ahead with its drone programme to combat militant threats.

Obama said: "I will increasingly turn to our military to take the lead and provide information to the public about our efforts."

"When we cannot explain our efforts clearly and publicly, we face terrorist propaganda and international suspicion; we erode legitimacy with our partners and our people; and we reduce accountability in our own government."

US intelligence officials, speaking on condition of anonymity, told AP that although aerial surveillance by armed aircraft continues in Pakistan, there have been no attacks in recent months.

Stricter rules to prevent civilian casualties have also forced the CIA to reduce the number of attacks, reports suggest. Besides, militants sometimes use children as human shields.

CIA officials have not yet confirmed that they are easing the drone programme in Pakistan.