Syrian forces recaptured the town of Rabia Sunday, continuing their string of victories over rebels in the northwestern province of Latakia.
Rabia is about 10 kilometers south of the Turkish border and is one of more than a dozen areas the government said its fighters took control of in recent days.
The Britain-based Syrian Observatory for Human Rights, which monitors violence in Syria, said the pro-government troops were backed by Russian airstrikes and strategic help from Russian military officers.
In eastern Syria, the Observatory said Sunday that airstrikes by Russian and Syrian warplanes killed at least 164 people in the last three days in Deir Ezzor province.
The dead included 43 children in four separate towns.
Airstrikes on Raqqa
The Observatory also reported 44 deaths from Russian and Syrian airstrikes in Raqqa, the northern city that serves as the de facto capital for the Islamic State group.
The latest violence comes as the United Nations works to bring opposition groups and the Syrian government to Geneva for a new round of peace negotiations.
U.N. envoy for Syria Staffan de Mistura wanted the talks to begin Monday, but with disagreements over who will take part, the start will likely be delayed for at least several days. He plans to give a briefing Monday afternoon to update the situation.
The conflict has raged in Syria since March 2011 and left more than 250,000 people dead. Millions more have fled the country, while many of those who remain are in need of humanitarian assistance.