When news flashed of an air strike on a vehicle in the Yemeni city of Radaa on Sunday afternoon, early claims that al-Qaida militants had died soon gave way to a more grisly reality.

At least 10 civilians had been killed, among them women and children. It was the worst loss of civilian life in Yemen's brutal internal war since May 2012. Somebody had messed up badly. But was the United States or Yemen responsible?

Local officials and eyewitnesses were clear enough. The Radaa attack was the work of a US drone – a common enough event. Since May 2011, the Bureau of Investigative Journalism has recorded up to 116 US drone strikes in Yemen, part of a broader covert war aimed at crushing Islamist militants. But of those attacks, only 39 have been confirmed by officials as the work of the US.

The attribution of dozens of further possible drone attacks – and others reportedly involving US ships and conventional aircraft – remains unclear. Both the CIA and Pentagon are fighting dirty wars in Yemen, each with a separate arsenal and kill list. Little wonder that hundreds of deaths remain in a limbo of accountability.

With anger rising at the death of civilians in Radaa, Yemen's government stepped forward to take the blame. It claimed that its own air force had carried out the strike on moving vehicles after receiving "faulty intelligence". Yet the Yemeni air force is barely fit for purpose.

And why believe the Yemeni defence ministry anyway? Just 48 hours earlier it had made similar claims. But when it emerged that alleged al-Qaida bomber Khaled Musalem Batis had died in a strike, anonymous officials soon admitted that a US drone had carried out that killing.

There is a long history of senior Yemeni officials lying to protect Barack Obama's secret war on terror. When US cruise missiles decimated a tented village in December 2009, at least 41 civilians were butchered alongside a dozen alleged militants, as a parliamentary report later concluded.

As we now know, thanks to WikiLeaks, the US and Yemen sought to cover up the US role in that attack. We'll continue saying the bombs are ours, not yours," President Saleh informed US Central Command (Centcom)'s General Petraeus.

Pakistan's own former strongman, General Pervez Musharraf, had performed a similar deed for the CIA, with the army claiming early US drones strikes as its own work. A senior Musharraf aide told the Sunday Times, "We thought it would be less damaging if we said we did it rather than the US." Only when civilian deaths became too unbearable in 2006 did Islamabad end that charade.

Still, dictators may have been better able to rein in US covert attacks than their democratic successors. When US special forces accidentally killed Jaber al-Shabwani, the deputy governor of Yemen's Marib province in May 2010, Saleh was able to secure a year-long pause in the US bombing campaign.

With new president Abd-Rabbuh Mansour Hadi owing his position to the US he is unlikely to enjoy similar leverage, if Pakistan's present impotence against CIA strikes is any guide.

The odds of finding out who was really responsible for Sunday's deaths are not good. At the height of this year's US-backed offensive against al-Qaida in May, at least a dozen civilians died in a double air strike in Jaar. As onlookers and rescuers came forward after an initial attack, they were killed in a follow-up strike.

The event was reminiscent of CIA tactics in Pakistan, and there is circumstantial evidence that US drones carried out the attack. Times reporter Iona Craig recalls the testimony of one survivor she met in Jaar:

"He didn't know who carried out the strike but said they didn't hear any planes or fighter jets before either strike and they dived to the ground when they saw a 'missile' with a jet stream of 'white smoke behind it', flying through the sky towards them before the second strike happened'."

Four months on, neither Yemen nor the US has taken responsibility for that attack. According to Haykal Bafana, a lawyer based in Sanaa, "the greatest worry for people here is not only a lack of accountability but a lack of transparency. Civilians at risk in the areas being targeted are being given no information at all about how best to protect themselves."

There is also the issue of compensation. Yemen's government has now ordered an inquiry into the Radaa bombing. Yet following the 2009 killing of 41 civilians relatives were compensated with just a few hundred dollars, after details of Centcom's role were deliberately hidden from that inquiry. In contrast, US forces in Afghanistan not only admitted responsibility in a recent incident, but paid out $46,000 (£29,000) for each person killed and $10,000 for those injured.

There is a growing gulf between what Yemen's people are experiencing and what their government claims. Bafana says Yemen's official news agency Saba has only used the word "drone" once since February 2011. A confirmed US strike on August 29 killed not only three alleged militants but a policeman and a local anti-al-Qaida imam, according to local reports. Those civilian deaths remain absent from Saba's coverage.

The US in turn greets queries with obfuscation. The CIA declined to comment when asked whether it had carried out the lethal attack on Radaa, or had ever paid out compensation for collateral damage. And a senior Pentagon spokesman, declining to comment "on reports of specific counterterrorism operations in Yemen", referred any queries back to Yemen's government.

In the aftermath of Sunday's disastrous air strike, relatives of the dead threatened to lay the corpses of the victims in front of the country's new president. And local activist Nasr Abdullah told CNN: "I would not be surprised if 100 tribesmen joined the lines of al-Qaida as a result of the latest drone mistake. This part of Yemen takes revenge very seriously." Civilian deaths risk undoing all that the United States is trying to achieve in Yemen – and an absence of true accountability is making matters worse.