BEIRUT — Hundreds of civilians fled a mountainous region outside the Syrian capital on Sunday, where government forces were battling several insurgent groups, including an Al Qaeda-linked unit excluded from a recent nationwide cease-fire.

The Syrian military said some 1,300 people have fled the Barada Valley since Saturday.

The region has been the target of days of airstrikes and shelling despite the truce, which was brokered by Russia and Turkey and appears to be holding in other parts of the country, despite some reports of fighting.

The truce went into effect early Friday, and the government and the opposition are expected to meet for talks in Kazakhstan later this month. Russia, a key military ally of Syrian President Bashar Assad, and Turkey, a leading sponsor of the rebels, are acting as guarantors of the agreement, which excludes the al-Qaida-linked Fatah al-Sham Front and the Islamic State group.

On Saturday, the UN Security Council unanimously adopted a resolution supporting efforts by Russia and Turkey to end the nearly six-year conflict in Syria and jump-start peace negotiations.

The military said those fleeing the Barada Valley were relocated to safer areas and their names were registered by the Syrian Arab Red Crescent.

Rami Abdurrahman, who heads the opposition’s Britain-based Syrian Observatory for Human Rights, said there were buses ready to evacuate civilians but could not confirm how many people had left.

He said the Barada Valley is not part of the cease-fire because of the presence of Fatah al-Sham Front, formerly known as the Nusra Front.

The Barada Valley Media Center said Lebanese Hezbollah militants were firing on villages and towns in the water-rich area as Russian and government aircraft carried out raids for the 10th consecutive day Saturday. The Lebanese militant group has sent thousands of fighters to Syria to bolster Assad’s forces.

The Barada Valley is the primary source of water for the capital and its surrounding region. The government assault has coincided with a severe water shortage in Damascus since Dec. 22.

Images from the valley’s Media Center indicate its Ain al-Fijeh spring and water processing facility have been destroyed in airstrikes.

The government says rebels spoiled the water source with diesel fuel, forcing it to cut supplies to the capital.

The Observatory and the Aleppo Media Center, an activist collective, meanwhile reported government airstrikes on rebel-held villages near the northern city of Aleppo, which was recently returned to full government control.

State news agency SANA said two suicide attackers blew themselves up in the coastal city of Tartus, killing two security officers who had stopped them shortly after midnight, as residents were celebrating New Year’s Day.

Such attacks are not uncommon in government-held parts of Syria despite tight security measures taken by authorities. Tartus is home to a Russian naval base.

Also Sunday, a news website close to Iran’s Revolutionary Guard said General Gholam Ali Gholizadeh, a veteran of the Iran-Iraq war in the 1980s, was killed fighting in Syria. Iran is also closely allied with Assad.

The resolution adopted by the UN Security Council on Saturday also calls for the ‘‘rapid, safe, and unhindered’’ delivery of humanitarian aid throughout the country.

And it anticipates a meeting of the Syrian government and opposition representatives in Kazakhstan’s capital, Astana, in late January.