Syrian and Russian jets are stepping up strikes on opposition forces in northern Syria in retaliation for the sudden offensive that has cost the regime control of the country’s second largest city, Aleppo.

The Syrian civil war, seemingly frozen in an uneasy deadlock for years, has been reignited with rebel forces wresting Aleppo, the country’s second biggest city, from President Bashar al-Assad ’s grasp.

Turkey’s foreign minister says the recent rapid advance by opposition fighters in Syria shows that the country must reconcile and hold dialogue with the opposition.