Insurgents breached Syria’s largest city Friday and clashed with government forces for the first time since 2016, according to a war monitor and fighters, in a surprise attack that sent residents fleeing and added fresh uncertainty to a region reeling from multiple wars.

Russian forces in Syria are under attack from rebel groups in the Syrian capital, Aleppo, in response to increased strikes.

Syrian rebels have swept through parts of the country at lightning pace, taking control of the the second-largest city, Aleppo. But who are they and what are their aims?

Syrian government forces pressed a counterattack against Islamist-led rebels around the key city of Hama on Wednesday after suffering a string of staggering losses further north, a war monitor said. The Britain-based war monitor said government forces backed by air support launched a counterattack on the HTS rebels and allied factions in Hama province on Wednesday.

The Syrian government, backed by Russian planes and their allies among pro-Iranian militias, has thwarted some rebel advances in the northern countryside around the city of Hama, a Syria commander told dpa on Tuesday.