Fierce fighting has broken out around the northern Syrian city of Aleppo after rebels launched a large-scale offensive to break the government's nearly two-month siege of opposition-held areas.
A reporter inside the city with Lebanon-based Al-Mayadeen TV reported attacks on "all sides" of the city, "from the furthest points north to furthest south".
Heavy gunfire, mortar fire and explosions were heard in the background of his broadcast, and dark smoke was seen rising above the city. Presumed government or Russian jets were also heard flying overhead.
The Syrian army said in a statement that troops had repelled rebel attacks on all fronts and inflicted human losses among the attackers.
The latest attack began with rebels detonating three vehicle-borne explosives at government positions to the city's south west and attacking with hundreds of rockets, the Britain-based Syrian Observatory for Human Rights said.
It said at least one of the vehicles was driven by a suicide bomber from the al Qaida-linked Fatah al-Sham Front, which had announced the offensive.
The Observatory said at least 15 civilians were killed in the rebel bombardment, and more than 100 wounded .
Syrian state media said pro-government forces had repelled the rebel attack as well as a militant attack by the Islamic State group near the city.
The Sana news agency reported that the military and allied militias thwarted assaults on several fronts around government-controlled western districts of the city, while also repelling an IS assault on an air force academy to the east.
"The Syrian army and its allies are in control on the ground and armed groups were not able to change the map," the army statement said. "Fighting is still ongoing but the intensity dropped."
This is the second attempt by rebels to break the government's siege. They opened a corridor to the east in August after pro-government forces applied a blockade in July, but government forces reinstated the siege in early September.
Fatah-al-Sham claimed credit for two car bombs, saying in a statement that a "martyrdom-seeking fighter" from France drove a tank laden with explosives and parked it near government positions then detonated it from a distance.
A spokesman said the Frenchman then drove another tank into the same place and detonated himself .
The Britain-based Syrian Observatory for Human Rights confirmed that a Frenchman carried out a suicide attack.
Fatah-al-Sham said a suicide car bomb attack was also carried out west of Aleppo.
The Islamic Front rebel coalition announced on Twitter that the ultra-conservative Ahrar al-Sham group had targeted a military airport to the east of the city with Grad rockets and destroyed a government position to the west of the city.
Ammar Sakkar, military spokesman for the powerful Fastaqim faction inside the city, said "all the revolutionary factions, without exception, are participating in the battle".
He said hundreds of advance fighters were involved, adding that the total number of participants was "much higher".
Sana said seven civilians had been killed by rebel shelling on government-controlled areas, and 70 others injured.
The battle came as the Russian, Syrian and Iranian foreign ministers met in Moscow.
Iran and Russia are president Bashar Assad's main backers and have committed air power, ground forces and military advisers to the war.
The government has maintained a siege on the rebel-held eastern quarters of Aleppo since September, and the UN estimates 275,000 people are trapped inside with dwindling supplies of food and medicine.
Russia's Sergey Lavrov said the three countries had agreed to intensify the fight against terrorism in Syria after his meeting with Syrian counterpart Walid al-Moallem and Iran's Javad Zarif.
Mr Lavrov said at a news conference that the fight would come in parallel with efforts to improve humanitarian aid.
He also reiterated Russian denials that its planes were responsible for an attack on a school in Idlib province that the UN children's agency said killed 22 children and six teachers.
Mr al-Moallem said government forces could agree to another cessation of fighting around Aleppo, but only if it receives guarantees from rebel forces that civilians would be allowed to leave the city.
Meanwhile a spokesman for Vladimir Putin said the Russian president had rejected a military request for the resumption of air strikes on rebel positions in Aleppo.
Dmitry Peskov said Mr Putin considers it "inadvisable to resume air strikes" and wants to have humanitarian corridors out of Aleppo's rebel-held districts stay open both for rebels and civilians to leave the city.
Mr Peskov noted that the "humanitarian pause" will give Washington time to honour its pledge to separate moderate rebels from al Qaida-linked militants in eastern Aleppo.