Assad, the Syrian dictator, to retake Aleppo after part of the city fell to insurgents in 2012. Less than four days is how long it took him to lose it. On November 27th rebels launched a surprise offensive in north-west Syria.

Over a few days, rebel fighters in northern Syria have launched incursions into several major cities with little resistance from government troops.

The Syrian army said on Saturday dozens of its soldiers had been killed in a major attack by rebels who swept into the city of Aleppo, forcing the army to redeploy in the biggest challenge to President Bashar al-Assad in years.

Syria’s rebels seized most of Aleppo on Saturday as their sweeping advance ousted Russian forces from at least three military bases around the city. Opposition fighters raced through Aleppo, Hama and Idlib provinces in a lightning advance that has stunned Bashar al-Assad’s regime.

The British-based monitoring group, the Syrian Observatory for Human Rights (SOHR), said that more than 300 people had been killed since the start of the offensive launched by militant group Hayat Tahrir al-Sham (HTS) and allied factions on Wednesday in which dozens of villages have been seized.

AMMAN (Reuters) -Russian and Syrian warplanes targeted insurgents in an Aleppo city suburb on Saturday, two Syrian military sources said, after the rebel fighters penetrated the heart of the city in Syria's northwest in a surprise attack the previous day.

Rebel forces in Syria have seized control of most of the city Aleppo after launching a surprise offensive against government forces, a war monitor reported on Saturday as Russia says it deployed fighter jets against rebels in Syria.

Russia appears to be "letting the Syrian rebels overthrow" President Bashar al-Assad according to Richard Grenell, who served as acting director of National Intelligence for a time during Donald Trump 's first administration.

The insurgent offensive, shocking for its speed, has posed the most serious challenge to President Bashar al-Assad in years.