More than 500,000 people are estimated to have fled to the northern city of al-Raqqa over the year-and-a-half long conflict in Syria.

That influx of internally displaced Syrians has doubled al-Raqqa's population.

Now, as opposition fighters say they plan to take the city from the forces of President Bashar al-Assad, civilians are pleading with the fighters to spare them the violence that would ensue.

Al Jazeera's Andrew Simmons reports exclusively from Tal Abyad on the Turkish border, from where the opposition forces are trying to advance.