UN human rights investigators accused the Syrian government of a campaign of "enforced disappearances" against thousands of civilians in a recent report. The UN notes the phenomenon may constitute a crime against humanity.
In response, rebel groups such as the Al Qaeda affiliated Islamic State in Iraq and the Levant (ISIS) have started capturing people as well. Recently, the ISIS was exposed to be operating secret prisons in which civilians are tortured and killed.
The report, by the Independent International Commission of Inquiry on the Syrian Arab Republic, is based on evidence from defected Syrian army officers and families of abducted citizens, notes BBC.
The study found "enforced disappearances are perpetrated as part of a widespread campaign of terror against the civilian population," adding the disappearances are likely "committed by government forces...against the civilian population, and therefore amount to a crime against humanity."
Meanwhile the army has been bombarding Aleppo in airstrikes, which Doctors Without Borders estimate have killed 189 people since starting Sunday. Reportedly the Syrian army has been using "exploding barrels," a crudely improvised yet lethal explosive dropped by helicopter.
However, Russia once again blocked a UN Security Council resolution against the Aleppo conflagration on Thursday.
Regarding crimes against humanity, UN inspectors last Thursday confirmed that chemical weapons have been used at least 5 times during the Syrian conflict.
The Syrian war, now in its third year, has left over 100,000 dead and created over 2 million refugees.
Recently the UN appealed for a record $6.5 billion in humanitarian aid for Syrians, the most it has ever asked for over a single crisis.