The strikes on Saturday targeted an Al-Nusra Front building near a popular market in northwestern Idlib province, according to the Syrian Observatory for Human Rights.
The complex in Maarat Al-Numan housed the group's religious court and a jail.
The dead included 23 Al-Nusra fighters and six non-jihadist rebels who were in the building.
Another 52 people -- including civilians and prisoners in the complex -- were also killed.
Russian warplanes have been conducting air strikes against the Islamic State organisation and "other terrorist groups" in Syria since September 30.
Although Al-Nusra and IS are both jihadist organisations, they are fierce rivals and regularly clash in Syria.
Al-Nusra also has tense relationships with non-jihadist rebel groups that oppose its extreme interpretation of Islamic law.
In Idlib, it heads a coalition of Islamist and rebel groups known as the Army of Conquest which has expelled regime forces from the province.
Syria's conflict first erupted with anti-government demonstrations in March 2011 but expanded into a war that has left more than 260,000 people dead.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
