The life sentence handed down by a German court on Thursday to a former Syrian colonel for crimes against humanity in his war-torn country marks a "landmark leap" towards justice, the UN rights chief said.
UN High Commissioner for Human Rights Michelle Bachelet said the verdict handed to Anwar Raslan, 58, at the end of the first global trial over state-sponsored torture in Syria was "historic".
"Today's verdict should serve to spur forward all efforts to widen the net of accountability for all perpetrators of the unspeakable crimes that have characterised this brutal conflict," she said in a statement.
Raslan was found guilty of overseeing the murder of 27 people at the Al-Khatib detention centre in Damascus, also known as "Branch 251", in 2011 and 2012.
Prosecutors accused him of overseeing the murder of 58 people and the torture of 4,000 others at the centre, but not all of the deaths could be proven.
"This trial cast a much-needed, renewed spotlight on the kinds of sickening torture, cruel and truly inhuman treatment -- including abject sexual violence -- that countless Syrians were subjected to in detention facilities," Bachelet said.
"It is a landmark leap forward in the pursuit of truth, justice and reparations for the serious human rights violations perpetrated in Syria over more than a decade."
The case was brought using the legal principle of universal jurisdiction, which allows offences to be prosecuted even if they were committed in a different country.
"This is a clear example of how national courts can and should fill accountability gaps for such crimes wherever they were committed," Bachelet said.
"This serves as a powerful deterrent and helps prevent future atrocities."
There have been a number of other criminal and civil cases against former officials and non-state actors in various conflicts, brought in Germany and in a number of other European countries.
The UN rights chief urged more countries to take advantage of universal jurisdiction and take on investigating and prosecuting serious rights abuses.
Thursday's conviction, she said, "has put state authorities on notice: no matter where you are or how senior you may be, if you perpetrate torture or other serious human rights violations, you will be held accountable sooner or later, at home or abroad."