The Syrian government is denying reports that rebel fighters are advancing in Hama after taking over most of Aleppo province.

Hundreds of fighters from Iran-backed Iraqi militias have crossed into Syria to help the regime of Bashar al-Assad fight off an insurgency across much of the northwest of the country, which has seen the seizure of the second city of Aleppo.

The Syrian military rushed reinforcements to the northwest and launched airstrikes Sunday in an attempt to push back insurgents who seized the country’s largest city of Aleppo.