Syrian rebels in the last opposition enclave in northern Syria launched on Wednesday a wide-scale military operation against the Syrian army and seized territory in the first such advance in years, army and rebel sources said. The rebel offensive overran at least 10 areas under the control of Syrian President Bashar al-Assad in northwestern Aleppo province, said a source in the operations room run by a coalition of insurgent groups led by the militant Hayat Tahrir al-Sham.