DAMASCUS, Syria — Fighting shattered a fragile three-day truce Aug. 15 as military operations resumed on three fronts: the Syrian regime and its Iranian-backed Lebanese ally Hezbollah against opposition fighters in the mountain city of Zabadani and the opposition's Ahrar al-Sham movement in the two pro-regime, Shiite-majority cities of al-Fawaa and Kefraya in the province of Idlib.

The truce began Aug. 12 to allow negotiations between Ahrar al-Sham and an Iranian delegation in Turkey.

Zabadani is vital for the Syrian regime and Hezbollah, given its location in Damascus’ western countryside and on the international road between Damascus and Beirut controlled by the Syrian regime forces. The town is also close to the Lebanese border and multiple Shiite villages on the Lebanese side, prompting a Hezbollah military operation similar to one it had waged in Qusair in June 2013 in the western countryside of Homs.

Ain Jaber, an activist in Zabadani, told Al-Monitor, “Zabadani has been subject to heavy artillery shelling from al-Atassi and al-Muaskar checkpoints since the morning of Aug. 15, after the end of the truce period and the failure of the negotiations.”