Syria Conflict: Troops 'Cross Into IS-Held Raqqa Province'
Syrian troops have crossed into Raqqa province, nearing the capital of so-called Isis, activists say.
The UK-based Syrian Observatory for Human Rights said heavy Russian air strikes had helped the offensive. There is no Syrian or Russian confirmation.
A US-backed alliance of Syrian Kurdish and Arab fighters started a campaign in May to expel Isis militants from land north of Raqqa.
Isis seized the city in 2013 from rebels opposed to President Bashar al-Assad.
The jihadist group quickly established its headquarters there and began imposing its vision of a state, implementing a strict interpretation of Islamic law.
It proclaimed a "caliphate" in 2014.
The Syrian Observatory said there had been clashes with Isis militants on the Athria-Tabqa road as the Syrian troops moved from Hama province in the south-west.
The Syrian military were trying to reach Lake Assad and the main road linking Raqqa to Aleppo.