DAMASCUS, Syria—A fragile cease-fire in the northern Syrian city of Aleppo has been extended for 72 hours, Russia said Saturday, as Islamic State fighters battled other militant factions near the city.

The Russian Defense Ministry said in a statement that the extension was made at Moscow’s initiative and would also apply to the coastal province of Latakia. The truce is now in effect until 12:01 a.m. local time on Tuesday, or 5 p.m. ET on Monday.

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