U.S. officials do not publicly acknowledge the CIA's covert drone program, but they have said privately that the strikes harm very few innocents and are key to weakening al-Qaida and other militants.
"I have tried covering the important but uncovered and unreported truth about drone strikes in Pakistan: that far more civilians are being injured and killed than the Americans and Pakistanis admit," said Noor Behram, a 39-year-old photographer who has worked with several international news agencies.
Behram spent the last three years photographing the aftermath of drone strikes in North and South Waziristan, important sanctuaries for al-Qaida and Taliban militants in Pakistan. He managed to reach around 60 attack sites, and the exhibit that opened Tuesday at the Beaconsfield gallery in London features photographs from 28 of those strikes.
U.S. officials "don't see that they target one house and along with it, two or three adjoining houses also get destroyed, killing innocent women and children and other totally impartial people," Behram told reporters in Islamabad on Monday.
It is often difficult to verify who is killed in the strikes because the areas where they occur are dangerous and off-limits to foreign journalists. News agencies often rely on local intelligence officials to determine who perished in a strike.
The exhibition is sponsored by the British rights group Reprieve and by the Foundation for Fundamental rights, an NGO started by Pakistani lawyer Mirza Shahzad Akbar to help drone strike victims.
The exhibit includes a photo showing an 8-year-old boy allegedly killed in a drone strike in 2009 in South Waziristan, his body surrounded by flowers as it was prepared for burial. Another showed a man in North Waziristan holding what is described as a piece of a missile fired from a U.S. drone, with the rubble of several destroyed mud buildings behind him.
Other photos in the exhibit are more gruesome.
A poll conducted last year in the tribal region by two U.S.-based organizations, the New America Foundation and Terror Free Tomorrow, found that more than three-quarters of the residents surveyed opposed the U.S. missile strikes, and nearly half thought they mainly kill civilians.
But some analysts and activists have suggested people in the tribal region are not free to express their true views about the missile strikes because they fear Taliban reprisal.
One political and human rights activist from the Khyber tribal region, Lateef Afridi, said last year that he has found particularly strong support for missile strikes among people he has met from North Waziristan, where most of the attacks have been focused recently.
Akbar, the Pakistani lawyer backing the exhibit, has sought to bring lawsuits against CIA officials connected with the drone program. He filed a report to Pakistani police Monday calling for an international arrest warrant for John Rizzo, the CIA's former chief counsel. Last year, Akbar filed a similar report against the CIA chief in Pakistan, prompting the spy agency to withdraw him from the country.
Pakistani officials regularly criticize the drone strikes as violations of the country's sovereignty. But the government is widely believed to have supported them in the past — a position that has become strained in the wake of the covert U.S. raid that killed Osama bin Laden on May 2 and humiliated Pakistan.
Reprieve's director Clive Stafford Smith said he believes the drone strikes are doing more harm than good in Pakistan.
"I hate to expose the world to pictures of a child with his head blown half off, but that is what the U.S. military calls 'collateral' damage," said Smith. "This is another terrible U.S. policy in the war on terror."