ISLAMABAD: The US campaign of drone strikes in Pakistan’s northwestern tribal belt is terrorising civilians 24 hours a day and breeding bitter anti-American sentiment, researchers said Tuesday.

The attacks are largely based in northwest Pakistan, where militants linked to Taliban and al Qaeda have strongholds have killed thousands of people since they began in June 2004, says a report by experts from Stanford Law School and the New York University School of Law.

Aside from casualties, the “Living Under Drones” report said, the missile strikes are affecting daily life in the tribal areas, making people unwilling to gather in groups – even for weddings and funerals – for fear of being targeted.

Drone strikes allow the US to carry out “targeted killings” of people it believes are militants from afar, without endangering American lives, but the campaign has become a festering sore in US-Pakistan relations, says the report by Stanford-NYU experts.

The report urged Washington to rethink its drone strategy, arguing it was counterproductive and undermined international law.

Based on media reports and interviews with residents of North Waziristan, one of the areas most heavily targeted by drones, the research said the US conception of the campaign as a “surgically precise and effective tool that makes the US safer” was false.

Drone strikes allow the United States to carry out “targeted killings” of people it believes are militants from afar, without endangering American lives, but the campaign has become a festering sore in US-Pakistan relations.

Islamabad says the strikes are counterproductive and a violation of its sovereignty, but US officials are believed to regard them as an effective way of disabling terror groups by killing key members.

The Stanford-NYU report said “the publicly available evidence that they have made the US safer overall is ambiguous at best” and the majority of militants killed by drones seemed to be low-ranking.

Reliable casualty figures are difficult to acquire in the tribal areas, which are off-limits to journalists and aid workers because of security worries and government restrictions.

Citing a CNN report, the Stanford-NYU paper said only around two per cent of those killed in drone strikes were “high-level” targets.

Total deaths between June 2004 and September 2012 were between 2,562 and 3,325, with 474 to 881 of them civilians, “Living Under Drones” said, quoting figures gathered from media reports by the London-based Bureau of Investigative Journalism.