Rebel forces have entered parts of Syria’s second-largest city, Aleppo, a monitoring group says, in the biggest offensive against the government in years.

The UK-based group says fighters set off two car bombs before advancing into neighbourhoods, without giving further details.

Government forces meanwhile say they have regained control of positions that had been taken by rebels in the Idlib and Aleppo countryside, Syria’s state news agency reported.

The Islamist militant group Hayat Tahrir al-Sham (HTS) and allied factions said they seized a number of towns and villages in Aleppo and Idlib provinces after launching the offensive on Wednesday.