On Tuesday, the Syrian Observatory for Human Rights said it estimated Syria’s current death toll at 162,000, with an increase of 10,000 over the past two months. The UK-based group, which bases its numbers on reports from a network of 200 contributors across Syria, says the figure includes 53,978 civilians, 8,607 of them children, 37,685 from the military and 23,485 from pro-government militias.

The Syrian Observatory also said that it had tallied 438 dead from Hezbollah, the Lebanese militia fighting on the government side, which has not cited a figure for its own losses. And the group said that 1,224 non-Syrian, pro-government fighters had also died. Iraqi and other foreign fighters, most of them Shiite Muslims, have flocked to the government side, much as foreign Sunnis have joined the insurgents.

It also gave rare numbers of fighters killed: 42,701 rebels, including more than 13,500 extremists, and, on the government side, 37,685 from the army and 23,485 from non-state armed militias.

Lama Fakih, Syria-Lebanon researcher for Human Rights Watch, weighs in on the main factors that contributed to the recent 10,000-death increase.

Syria Deeply: What are the major factors that have contributed to such a large spike over the past two months?

Lama Fakih: We don’t keep a tally of fatalities in the conflict because we don’t have the ability to confirm the exact numbers. What we have seen over the past couple of months is the intensification of offenses in the lead up to June’s elections. The government has been engaging in this aerial assault of Aleppo’s city and countryside, which has led to extensive civilian fatalities and injuries.

We have documented hundreds of incidents of barrel bombs being dropped on civilian populations in recent months. They have escalated this in the past week by using chlorine in some of the barrel bombs that fell on Hama. In cases we’ve documented, this has affected 500 people and caused 11 fatalities. So quite clearly, this intensification has had an affect over the past two months.

We’ve seen deadly attacks by a number of non-state armed groups, which continue their mortar attacks on territory [not held by the government], and some groups keep using car bombs, sometimes against civilians, which has resulted in extensive fatalities.

When we talk about fatalities we cannot forget the numbers of individuals who are being killed in detention. We are doing ongoing research on deaths in custody and government detention facilities, and we do receive reports of individuals being killed [regularly] in detention by torture and other mistreatment.

Syria Deeply: Have aid restrictions been a factor?

Fakih: Despite a Feb. 22 U.N. Security Council measure to boost humanitarian aid access in Syria, there hasn’t been a measurable difference because the Syrian government still will not allow the U.N. to use cross-border expeditions to help civilians in hard to reach areas, and because sieges are still being imposed on civilian populations in the Damascus countryside and elsewhere. Some sieges have eased – the siege of the Old City of Homs ended – but there were also some restrictions placed, as a result of that Homs deal, on two Shia areas [already] under siege by nonstate armed groups. But the overall pattern of government-imposed sieges continues to affect thousands of civilians.

Syria Deeply: How has Syria’s crumbling medical infrastructure played in, or the resurgence of deadly diseases?

Fakih: We’ve seen that the Syrian medical infrastructure has also been a target of attacks, with both doctors and facilities targeted and attacked. This has meant that individuals who have war injuries and those suffering from chronic diseases are struggling to get access to basic service. There is an overwhelming need for medics to respond to incidents as they happen. Patients that require dialysis or other long-term care aren’t getting it, hospitals need to rely on generators that sometimes fail. We have seen the resurgence of diseases including polio and leishmaniasis, and the absence of adequate mechanisms to vaccinate or treat them.

Syria Deeply: Do you expect the numbers to taper off after elections?

Fakih: The intensification of fighting in the lead up to elections [is the biggest contributing factor], absolutely. We see that violence begets violence. When the government launches indiscriminate attacks, it often has resulted in retaliatory attacks by nonstate armed groups that have had deadly consequences. The concern going forward after June 3 is that both sides continue to act with impunity and fail to meet their basic obligations under international humanitarian law.