Rival rebel militias in northwest Syria have reached a preliminary ceasefire and joint administration agreements after days of widespread deadly clashes between them, military sources have told The New Arab’s Arabic-language sister site. Hardline Islamist extremist group Hay’at Tahrir al-Sham (HTS) and the Third Corps of the Turkish-backed Syrian National Army reached the agreement on Friday night, a military source from the Third Corps told Al-Araby Al-Jadeed. The preliminary agreement included a ceasefire and the return of each faction to their former locations, the military source said. HTS…