Half of 300 UN observers monitoring the situation in Syria have left the country. That’s according to UN’s Under-Secretary-General for Peacekeeping Operations Herve Ladsous.

On July 21, the UNSC ruled to extend the mission by 30 more days. The original contingent of 300 observers arrived in Syria in April, with a brief to patrol the country and ensure a ceasefire.

The conflict in Syria is ongoing since March 2011. The UN estimated that over 16,000 people have been killed during this time.