Syrian government forces have taken control of a major town in the coastal province of Latakia, as fierce fighting continues in areas across the country.

The Britain-based Syrian Observatory for Human Rights said forces loyal to Syrian President Bashar al-Assad regained control of Kinsabba on Saturday as Russian air strikes backed them.

Syrian journalist Eyad al-Hosain, who is embedded with the troops, said government forces now control Kinsabba and the hills surrounding it, southwest of the city of Jisr al-Shughur. He wrote on his Facebook page that the battle lasted 12 hours.

Syrian government forces first captured Kinsabba in February after it was held by rebels for weeks.

Rebels, including members of al-Qaeda’s branch in Syria, regained control of the town on July 1.

In the divided city of Aleppo, air strikes killed at least 20 civilians, including five children, in the eastern, opposition-held neighbourhoods.

The Syrian conflict started as a mostly unarmed uprising against Assad in March 2011, but it quickly evolved into a full-scale civil war.

An estimated 280,000 people have died throughout the five-year conflict, the Syrian Observatory estimates.

US-Russia cooperation

The continued fighting came one day after US Secretary of State John Kerry said his country and Russia agreed to cooperate in Syria against the al-Nusra Front, the Syrian affiliate of al-Qaeda.

Kerry said the details of the agreement “define specific, sequential responsibilities all parties to the conflict must assume with the intent of stopping, all together, the indiscriminate bombing of the Assad regime and stepping up our efforts against al-Nusra”.

Syrian rebel groups, including the Free Syrian Army, insist there is no military cooperation with al-Nusra.

Syrian journalist Mahmoud Al Basha said al-Nusra has tried to “mix” with other rebels as part of a strategy.

“They will be among these groups, so it will be very difficult for air strikes … and Western countries bombing them and targeting them,” he told Al Jazeera.

Al Jazeera’s Zeina Khodr, reporting from Gaziantep in neighbouring Turkey, says targeting the armed group “won’t be easy”.

“In some areas, al-Nusra shares territory with the opposition and is embedded with them on the battlefield,” she said. “In other areas, al-Nusra has local alliances with factions that are backed by the US and some Arab countries.”