An ambush on a Syrian security patrol by gunmen loyal to ousted leader Bashar Assadescalated into clashes that a war monitor estimates have killed more than 1,000 peopleover four days. The attack Thursday near the port city of Latakia reopened the wounds of the country’s 13-year civil war and sparked the worst violence Syria has seen since December, when insurgents led by the Islamist group Hayat Tahrir al-Sham, or HTS, overthrew Assad.