The United Nations acknowledged on Tuesday that it has stopped updating its death toll estimates for the years-long Syrian conflict. That's because the international body, with limited access on the ground in the country, is no longer able to verify the sources of information it used to produce the estimates. 

The acknowledgement comes in response to a question from the Associated Press. The most recent figure from the U.N. — over 100,000 killed in Syria — was released in July. U.N. Office of the High Commissioner for Human Rights spokesperson Rupert Colville told the AP that his office previously relied on six different estimates from NGOs working in the region. Taking those figures and sources, the U.N. would attempt to verify whatever they could, and then update their estimate. But that's changed. "Over time, they've diminished in number," Colville said. "For the past year or so, it's been down to two or a maximum of three, and we simply didn't feel that it was possible for us to continue in the same way." He added: 

"It was always a very difficult figure. It was always very close to the edge in terms of how much we could guarantee the source material was accurate. And it reached a point where we felt we could no longer cross that line. So for the time being, we're not updating those figures."

The U.N. figures were one of two estimates widely cited in coverage of the Syrian conflict. So the U.N.'s announcement leaves news organizations with the Syrian Observatory for Human Rights's death count. The U.K.-based organization is basically just one (very busy) guy, Rami Abdul Rahman, who also isn't in Syria. According to a New York Times profile of the organization from earlier this year, Abdul Rahman uses a network of about 200 people on the ground in the country to verify information on possible casualties collected from a variety of sources — including news reports and YouTube videos. Basically everyone involved in the conflict accuses him of producing biased information, which might, counterintuitively be an endorsement of his methods. The Times writes: 

Activists in every province belong to a Skype contact group that Mr. Abdul Rahman and his aides tap into in an effort to confirm independently the details of significant events. He depends on local doctors and tries to get witnesses. On the telephone, for instance, speaking in his rapid-fire style, he asked one activist to visit a field hospital to count the dead from an attack. With government soldiers, he consults contacts in small villages, using connections from his youth on the coast among Alawites, the minority sect of Mr. Assad, which constitutes the backbone of the army.

The Syrian Observatory for Human Rights's latest count, updated last week, is 130,433, although the organization believes the actual death toll from the conflict is much higher, by at least 50,000. The latest toll includes 11,709 women and children, 29,083 armed rebel fighters, and 52,290 armed soldiers either from the Syrian army, or otherwise supporting Syrian president Bashar al-Assad. 

Meanwhile, fighting in northern Syria has intensified, but not between the rebels and Assad loyalists, but between competing rebel groups. A coalition of Free Syrian Army groups are trying to expel the al Qaeda-affiliated Islamic State in Iraq and Syria (ISIS) from a handful of rebel-held cities. The next round of UN-arranged Syria peace talks are scheduled to begin later in January, although at least one influential rebel-affiliated group, the Syrian National Council, has indicated that it might not attend unless the West does more to push Assad from power.