<span style="color: #222222;">Syria's Kurds have warned that the thousands of foreign jihadists they have detained in their fight against the Islamic State group are a time-bomb and the international community urgently needs to defuse it. </span><br />'' <br />'' <span style="color: #222222;">Speaking a day after Kurdish-led forces announced the final demise of the jihadists' physical "caliphate", the Kurdish administration's top foreign affairs official Abdel Karim Omar today warned that its foreign captives still pose a threat for them as well as the international community. </span><br />