Turkish artillery again hit targets in Syria on Thursday morning in reprisal for cross-border fire that killed five Turkish civilians the previous day, a security source said. "Artillery fire resumed at 03:00 GMT this morning," the source said on condition of anonymity. Several Syrian soldiers have been killed in Turkish fire, a watchdog said earlier. The Syrian Observatory for Human Rights said overnight shelling across the frontier by Turkish troops hit a Syrian army post near the border town of Tel Abyad. It gave no exact figure for the number of soldiers killed.