BEIRUT — A cease-fire brokered by the U.S. and Russia brought calm across much of Syria on Tuesday as residents of the northern city of Aleppo awaited an expected aid shipment.

Insurgent groups have expressed misgivings about the cease-fire, which would allow for strikes against a powerful al-Qaida-linked group that fights alongside the rebels. That group, formerly known as the Nusra Front, has condemned the truce, saying the deal is aimed at keeping President Bashar Assad in power.

SCATTERED VIOLATIONS

The Russian military said U.S.-backed rebels have repeatedly violated the cease-fire, with six people killed and 10 wounded in Aleppo since the truce began. It said two Syrian soldiers were killed and another wounded in a separate attack in Aleppo.

Syrian state media reported nearly two dozen violations by insurgents, mostly mortar attacks and sniper shots. It said insurgents attacked power lines in the southern Quneitra region, causing a province-wide blackout.

Turkey’s state-run news agency said two Syrians wounded in an attack by government forces were rushed across the border into Turkey for treatment.

ALEPPO AWAITS AID

U.N. envoy Staffan de Mistura hailed a “significant drop in violence” over the first 24 hours of the cease-fire, but said no U.N. aid trucks have yet moved across the Turkish border into Syria. He said U.N. officials are awaiting assurances that the drivers will be “unhindered and untouched.”

He said aid for rebel-held eastern Aleppo is a top priority, and that a key concern about the overall cease-fire is whether sporadic “incidents” snowball to threaten the deal.

Dozens of residents in the rebel-held part of Aleppo protested against the United Nations and demanded the lifting of the government’s siege of the area, which is home to some 250,000 people.

“Hunger is better than humiliation,” read one banner carried by the protesters.