WASHINGTON - US Human Rights activists have indicated that they might legally challenge the US militarys use of drones in Pakistan and Afghanistan in part because they say theres no warning to innocent civilians who are in a targeted area. Predator spy planes are unmanned aerial vehicles that are virtually invisible when flying overhead. Thats the spooky thing about the predator, national security and terrorism expert Neil Livingstone was quoted as saying by the Fox News. Even if the predator is directly overhead and you know its overheard, you still cant see it or hear it. This is kind of like death out of the blue. Gabor Rona, international legal director of HR First, a US-based group that advocates universal rights and freedom, said large number of civilians were being unintentionally hit, harmed and killed. This is not only a violation of the international laws of war, he was quoted as saying. Its bad policy. Opponents of the drones say that the policy could be illegal. The laws of war allow individuals who are engaged in hostilities to be targeted in an armed conflict but strictly prohibit actions against those not engaged. Even when youre attacking a legitimate military objective, you cannot cause civilian casualties that exceed the value of a legitimate military attack, Rona says. The Fox news said more civilians had been killed than actual al-Qaeda terrorists in 16 predator strikes this year. But theres little chance that could change. So many of these guys surround themselves with collateral casualties, Livingstone said, and large numbers of women and children were strategically placed around hotbeds of activity. He makes the point that even if high-value targets were killed in one of these drone attacks, al-Qaeda still could claim a 'propaganda victory because of the number of civilian casualties. Our military fighting in Afghanistan has got to be able to pursue high level (operatives) who flee across the border from Afghanistan into Pakistan, said Matt Bennett, a national security expert for a Washington-based think tank. On the presidential campaign trail, Obama had said that if there was legitimate intelligence about high-level al-Qaeda personnel he would not hesitate to act. And although theres no formal agreement between the US and Pakistan when it comes to Predator drone attacks, Pakistan more or less looks the other way. Even so, human rights advocates continue to grow more disillusioned by the presidents decisions on the Guantanamo military commissions and his refusal to release photos of alleged detainee abuse by US soldiers in Iraq and Afghanistan, as well as other national security issues. The Predator programme, which is a holdover from the Bush administration, could be the next legal battle. This is part of a broader campaign on the left to begin the drumbeat of withdrawal from Afghanistan and Pakistan generally to change the direction there and make it about only providing aid and not about military engagement, Bennett said.