Idlib is the last remaining opposition and rebel-held area in Syria, but the regime has warned of an offensive to regain control of the province.
Syrian opposition groups blew up bridges on Friday linking areas they control to regime-held territories in northwestern Syria in anticipation of a military offensive against their last stronghold in the country, activists and a war monitor said.
The explosions rocked the area in Al Ghab plains, south of Idlib and came after rebels detected regime forces movement in the area, according to Rami Abdurrahman, head of the war monitoring Syrian Observatory for Human Rights.
TRT World's Jacob Brown reports.
Abdurrahman said two other bridges remain in the area and could be used by regime forces to move in on the opposition and rebel stronghold.
Most of Idlib province and adjacent strips of Hama province remain in the hands of an assortment of armed groups, some Turkey-backed forces and other independent armed groups. But the strongest alliance of Hayat Tahrir al Sham, which is accused of having links to Al Qaeda, controls most of the area that is also home to some 3 million people.
Thousands of regime forces and allied militias have been amassing in areas surrounding Idlib while Russia, the regime's powerful ally, has said a military operation was necessary to weed out "terrorists" it blames for attacking its bases on the coast.
Turkey, which backs a number of opposition factions in Syria and has set up observation points that ring the rebel stronghold, has been seeking to curtail a full-scale offensive. Ankara fears a humanitarian and security crisis on its borders.
UN officials estimate an offensive would trigger a wave of displacement that could uproot up to 800,000 people. The area is already home to nearly 2 million displaced people previously from other parts of Syria.
The Observatory said Turkey-backed groups blew up the bridges as part of their reinforcement around the stronghold.
They have dug trenches, built berms and fortified their posts. Al Qaeda-linked authorities have also called on residents to take part in supporting the fighters, either through building reinforcements, volunteering to fight, or in field hospitals and kitchens to help men deployed on the frontline.
It also called on residents to take to the streets after Friday prayers against an offensive and in support of the fighters. Thousands protested in various towns in Idlib and Hama, denouncing threats of an attack and hailing the area's readiness to fight.
The campaign for Idlib is likely to be the last major theater of battle after seven years of brutal civil war.