Air strikes by regime and Russian aircraft on rebel positions in the northwestern province of Idlib kill at least 21 civilians, including eight children, a monitor says .
At least 28 people are reported to have been killed in an air strike on a refugee camp in rebel-held northern Syria, monitors say.
Turkey again summons the Russian ambassador after a second violation of its airspace by a Russian warplane operating in Syria in two days.
US President Barack Obama says the Russian bombing campaign in Syria in support of President Bashar al-Assad is driving moderate opposition underground and "only strengthening" Islamic State.
Air strikes by regime and Russian aircraft on rebel positions in the northwestern province of Idlib kill at least 21 civilians, including eight children, a monitor says .
At least 28 people are reported to have been killed in an air strike on a refugee camp in rebel-held northern Syria, monitors say.
Turkey again summons the Russian ambassador after a second violation of its airspace by a Russian warplane operating in Syria in two days.
US President Barack Obama says the Russian bombing campaign in Syria in support of President Bashar al-Assad is driving moderate opposition underground and "only strengthening" Islamic State.
