Between 29 and 45 people were reported killed by an apparent air attack at the al Mazraq camp – some were said to have been burned beyond recognition. Depressingly, the victims also included children.

Although the attack came shortly after Saudi Arabia had launched an aerial bombardment of Yemen, Yemen’s foreign minister, speaking from Riyadh, blamed artillery fired by the Houthi militia which stormed the country’s capital Sanaa late last year. A Saudi spokesman meanwhile said that rebels had been firing from a residential area in response to a question about the bombing.

Before answers could be found about what happened at al Mazraq, the violence quickly moved on elsewhere. Dozens of civilians were were reported killed by an attack on a dairy factory in Hodeida the following day. Again, the details are still unclear.

The potential for more such atrocities to be carried out with impunity is increasing as the Yemeni state collapses and regional powers pile in.

Saudi Arabia, convinced that the Houthis are backed by Iran, is leading an air campaign with a coalition of 10 Gulf neighbours and North African allies. Warships thought to belong to Egypt have reportedly shelled Yemen from the sea. US officials have pledged that drone strikes will continue. And al Qaeda is taking advantage of the chaos, springing hundreds of criminals from a prison in the east of the country.

It has never been more important, nor more challenging, to ensure proper mechanisms for the recording of casualties are in place.

The UN’s Office for Coordination of Humanitarian Affairs (Ocha) is doing the best it can. It is collecting, aggregating and publishing reports of casualties from any sources it can find. Its situation reports are providing vital insights into the bloodshed.

But it remains extremely difficult to record casualties from armed conflict accurately, even for the UN, which actually has its own staff in Yemen.

As Erich Ogoso, public information officer for Ocha Yemen, told the Bureau: “The biggest challenge is verifying information coming out of Yemen.”

The challenges stem, in part, from the lack of independent on-the-ground reporting to corroborate the proliferation of videos and tweets.

Perhaps paradoxically in the digital age, the fog of war has never been denser.

These are also the challenges the Bureau has faced over the past four years in recording deaths from the US’s ongoing war on terror in Pakistan, Somalia and Yemen itself.

We have tallied more than 400 US drone strikes in Pakistan since they began in 2004. And we have marked each reported drone, air and cruise missile strike in Somalia since 2007, and in Yemen since 2002.