Syria sent thousands of troops surging towards Aleppo in the early hours of Wednesday, where its forces have been pounding rebel fighters from the air, engulfing the country’s largest city in total warfare to put down a revolt.

Recent days have seen Syria’s 16-month-old uprising transformed from an insurgency in remote provinces into a battle for control of the two main cities, Aleppo and the slightly smaller capital, Damascus, where fighting exploded last week.

President Bashar al-Assad’s forces have launched massive counter assaults in the two cities. They appear to have beaten rebels back from neighborhoods in the capital and are turning towards Aleppo, a commercial hub in the north.

Syrian forces fired artillery and rocket barrages early on Wednesday at the northern Damascus suburb of al-Tel in an attempt to seize the town from rebels, causing mass panic and forcing hundreds of families to flee the area, residents and opposition activists said.

The 216th mechanized battalion headquartered near Tel started bombarding the town of about 100,000 people at 3:15 a.m. (0015 GMT) and initial reports indicated residential apartment blocks were being hit, they said. 

“Military helicopters are flying now over the town. People were awakened by the sound of explosions and are running away,” Rafe Alam, one of the activists, said by phone from a hill overlooking Tel. “Electricity and telephones have been cut off.”

“A large number of troops is being redeployed from Jabal al-Zawiya to Aleppo, which is strategically more important for the regime than Idlib,” the rebel Free Syrian Army’s Military Council spokesman in Aleppo told AFP via Skype.

The FSA’s Colonel Abdel Jabbar al-Oqaidi said he believed the reinforcements were being sent because of the intensity of clashes in Aleppo, where several districts were “liberated’ on Monday.

Rebels attacked the rear of the troops withdrawing from the region at the villages of Orom al-Joz and rami near the main Aleppo-Latakia road and at the village of al-Bara west of the Aleppo-Damascus highway, activist Abdul Rahman Bakran said from the area.

Meanwhile, around three people have been killed and up to 40 others injured in the central prison of Homs, which is being enfolded by the Syrian regime troops for days, activists told Al Arabiya. The Syrian forces shot at prisoners and used tear bombs, causing numerous fires inside and outside the prison. The prison has been witnessing a mutiny, during which four prisoners and a child were killed over the past few days.

Fifteen people had been killed by the Syrian forces in an equivalent mutiny in al-Maslamiya prison in Aleppo on Sunday night.

As many as 150 people have been killed by the fire of Syrian forces across the country. A new massacre was committed this time in al-Shareea village in Hama, activists at the Local Coordination Committees told Al Arabiya. The Syrian troops stormed the victims as they finished their Sunset prayers and were coming out of the mosque on Tuesday, killing at least 30 people, activists said, pointing out that dead bodies were sees in the streets surrounding the mosque.

In Aleppo, helicopters swirled overhead firing missiles throughout Tuesday, residents said. Rebels were battling government forces by the gates of the historic old city. Troops fired mortars and shells at rebels armed with rifles and machineguns.

“I heard at least 20 rockets fired, I think from helicopters, and also a lot of machinegun fire,” a resident near one of the areas being shelled, who asked to be identified only by his first name Omar, told Reuters by telephone.

“Almost everyone has fled in panic, even my family. I have stayed to try to stop the looters; we hear they often come after an area is shelled.”

Residents said fixed-wing jets had also flown over the city, followed by loud noises, although there were contradictory reports as to whether they had fired.

Some residents said they believed the planes had dropped bombs, but others said booming sounds could have been caused by supersonic jets breaking the sound barrier. A correspondent for Britain’s BBC television said the jets had fired.

Assad’s forces have occasionally launched air strikes from fixed-wing jets on other cities during the uprising, but tend to rely on helicopters for air strikes in urban areas.

The 16-month-old uprising has entered a new and far more violent phase in the past 10 days since rebels poured into Damascus in large numbers.

Meanwhile, defected Syrian Brigadier-General Manaf Tlas called on Syrians to unite and look towards a post-revolutionary Syria, in a statement broadcast on Al Arabiya late Tuesday.

“I speak to you as a defected member of the Syrian army, who refuses criminal violence … I speak to you as one of the sons of Syria,” .

The former general was believed to be speaking from Paris.

“Honorable Syrian army officers do not accept the criminal acts in Syria … Allow me to serve Syria after [President Bashar] al-Assad’s era.

“We must all unite to serve Syria and promote stability in the country, rebuilding a free and democratic Syria.”

“Allow me to call on a united Syria,” Tlas added.

Tlass said the “new Syria ... should not be built on revenge, exclusion or monopoly.”

He said he did not blame those troops who have not defected, adding that “whatever mistakes made by some members of the Syrian Arab Army ... those honorable troops who have not partaken in the killing ... are the extension of the (rebel) Free Syrian Army.”