Syria crisis: How is presidential election possible?

Syrians are heading to the polls in a presidential election, despite the country's ongoing civil war.

The election has been denounced by Western allies as an attempt to give Bashar al-Assad the veneer of electoral credibility.

Opposition areas are boycotting the vote, in which President Assad is widely expected to win another seven-year term in office.

Paul Wood reports from the rebel-held province of Idlib.