By Khalil Ashawi and Tom Perry
AZAZ, Syria/BEIRUT (Reuters) - Syrian insurgents carried out two suicide car bomb attacks in an assault on pro-government forces in Aleppo on Saturday and opened a new front northeast of the city, an attempted fightback after territorial gains for President Bashar al-Assad.
Backed by Russian air power, Syrian government forces had made a significant advance into the rebel-held northwest this week, seizing the town of Maarat al-Numan, part of an offensive to secure the main highway between Damascus and Aleppo.
The suicide attacks were carried out by jihadist group Hayat Tahrir al-Sham and targeted the Jamiyat al Zahraa area on the western edge of Aleppo. A third car bomb was set off by remote control, a source with the group said.
A news outlet linked to the group, Ebaa, published a video which it said showed elite Tahrir al-Sham fighters pledging "allegiance to death and jihad" before the attack on Jamiyat al-Zahraa, watched by the group's leader, Abu Mohammad al-Jolani.
The northwestern corner of Syria including Idlib province and adjoining areas of Aleppo is the last major rebel foothold in Syria, where Assad has taken back most of the ground once held by his enemies with Russian and Iranian support.
Syrian state news agency SANA said army troops had destroyed four car bombs before they reached their targets. Syrian army forces were firing rockets and artillery at militant groups on the Jamiyat al-Zahraa front, it said. Militants had also fired rockets at residential districts of Aleppo.
The two sides gave conflicting accounts of the outcome of the attack.
A news outlet run by Lebanon's Hezbollah, which fights in support of Assad, said the Syrian army had thwarted a "fierce attack" by the Nusra Front, as Jolani's group was known until it broke ties with al Qaeda in 2016.
But the jihadist-linked Ebaa news outlet said the attacking forces had captured a group of houses on a hill overlooking Aleppo.
GOVERNMENT CONTROL
The Hayat Tahrir al-Sham source said the attacks had targeted the "Iranian occupation militias", a reference to Iran-backed groups fighting in support of Assad.
Aleppo city has been under full government control since 2016, when pro-Damascus forces defeated rebels in the east of the city.
Some 50 km (35 miles) northeast of Aleppo, Turkish-backed rebels attacked government-held positions near the city of al-Bab, a rebel source and the Syrian Observatory for Human Rights reported. Turkish forces were not taking part, rebels said.
The government's latest offensive has triggered a fresh wave of civilian displacement, with hundreds of thousands moving towards the Turkish border.
Turkish President Tayyip Erdogan said on Friday Turkey may launch a military operation in Idlib unless the fighting there is halted.
The U.S. special envoy for Syria said on Thursday the Idlib fighting raised the spectre of an international crisis.
Turkey, which already hosts 3.6 million Syrian refugees, fears a fresh wave of migrants. It has 12 military observation posts around Idlib, set up under an agreement with Russia and Iran, and several of them have since been surrounded by advancing government forces.