Introducing the exhibition on Thursday night, Reprieve founder Clive Stafford Smith and Pakistani human rights lawyer Mirza Shahzad Akbar condemned the unmanned aircraft firing missiles in the North Waziristan region, which have resulted in more than 2,200 deaths, mostly innocent civilians.

Preliminary investigation by Reprieve human rights group suggests that the number of innocent victims may be far higher, and that contrary to American claims, the likelihood of the US hitting its intended “high-value terrorist” is low.

“Without doubt, the victims include a significant number of women and children,” said the London-based organisation which defends the human rights of prisoners from death row to Guantanamo.

To highlight the dangers of the attacks carried out by US soldiers and CIA civilians 13,000 km into a novel form of videogame warfare, Reprieve is promoting a new project “Bugsplat” the official term used by the US authorities when human beings are successfully killed with drone missiles.

“What is the US doing using drones in Pakistan anyway, given that the US is not at war with their ally?” said Stafford Smith, an award-winning British human rights lawyer.

The gallery of photographs was obtained by Akbar, an Islamabad-based lawyer representing drone victim families, who has been accumulating evidence on drone strikes and consulting with Reprieve on potential legal action.

“What we are discovering in our drone investigations is pointing towards culpability of not just Americans but also of their allies in this war of terror,” said Akbar, an advocate in Pakistan's High Court.

“By working with Reprieve we resolve to take these crimes to courts in the UK, the USA and international forums seeking justice for the loss of life of innocent people in Waziristan,” he said.

The Pakistani lawyer said that the evidence exposes an urgent need for a full and independent inquiry into the use of drones, as well as litigation in Pakistani and international courts.

“Our mission to Pakistan leads us to believe that American drones, guided by highly questionable US intelligence, indiscriminately kill innocent people, including children,” he said.

“Far from eliminating terrorism, we believe that when Americans play videogames with Pakistani lives this causes radicalization, and increases the danger to all, whether Pakistani or American.”

Both of the human rights groups are accumulating evidence, and believe that war crimes may have been committed against civilians who played no part in any conflict.