Syrian families whose loved ones were taken by Islamic State extremists are pressuring governments in the international coalition to help them learn the fate of their relatives.

The families on Tuesday announced the creation of a Paris-based organization to help document the missing, after a meeting with French diplomats. Khalil al-Haj Saleh, who is leading the group, said the end of fighting and the capture of thousands of Islamic State fighters leaves a small window to find and document what happened to their loved ones, who include Syrian activists and journalists.

The Syrian Network for Human Rights has documented more than 8,000 cases of people missing after being detained by the Islamic State group; hundreds, if not thousands, of bodies have been found in mass graves, but most are unidentified.