US defends drone strikes after Amnesty report documents civilian deaths

The White House insists the deaths of civilians in US drone strikes cannot be labelled a war crime and that the attacks against militants are precise and effective.

A joint report by Human Rights Watch and Amnesty International is calling on the US government to "come clean" on how many people it has killed.

The US has carried out hundreds of drone-assisted missile strikes, the numbers increasing during the presidency of Barack Obama.

White House spokesman Jay Carney has defended the administration's policies.

"They are lawful and they are effective and the United States does not take lethal strikes when we or our partners have the ability to capture individual terrorists," he said.

"Our preference is always to detain, interrogate and prosecute.

"We take extraordinary care to make sure that our counter-terrorism actions are in accordance with all applicable domestic and international law and that they are consistent with US values and US policy."

Mr Carney says the US is reviewing the report.

"To the extent these reports claim that the US has acted contrary to international law, we would strongly disagree," he said.

In May, Mr Obama spoke at the National Defence University and promised to narrow the parameters for the use of drones to limit collateral casualties.

It is a subject that is likely to be near the top of the agenda when he and Pakistan's prime minister Nawaz Sharif meet in Washington tomorrow.

Major cause of tension with Pakistan

The drone program has given the US major diplomatic headaches, especially with Pakistan which has publicly opposed the attacks.

Speaking in Washington, Mr Sharif said US drone strikes violate international law and "territorial integrity".

"Use of drones is not only a continued violation of our territorial integrity, but also detrimental to our resolve and efforts to eliminating terrorism from our country," he said.

"This issue has become a major irritant in our bilateral relationship as well."

The Human Rights Watch and Amnesty report's authors admit that each drone strike is difficult to verify.

Report documents cases of innocent civilians being killed

They have looked at a handful of cases and found multiple witnesses, including in the case of 68-year old Mamana Bibi who was killed on a sunny October day last year.

Amnesty International's Mustafa Qadri says she was doing nothing to warrant targeting.

"Her grandchildren recounted in painful detail to Amnesty International the moment when she was blown into pieces in front of their very eyes while she was gathering vegetables," he said.

Letta Tayler from Human Rights Watch spoke of the deaths in Yemen of 12 people travelling in a van.

She says the US was targeting an Al Qaeda militant.

"But that target was nowhere in sight. It turned out that all 12 people killed were villagers coming home from market," she said.

"Their loved ones found their charred bodies in pieces on the roadside, dusted in flour and sugar that they were bringing home to their families."

Amnesty says the US administration's secrecy makes reporting of the program difficult.

Spokeswoman Naureen Shah says there has been no new information from the government since May.

"We're asking president Obama to come clean about who the US government is killing, not just to make a pledge of transparency or make a promise that things are going right, but to say who is being killed, how many people have been killed and what the legal and factual justification for these killings was," she said.