The CityJet RJ's have wing and a center tank, max total fuel of around 9000kg, but not the aux tanks.
Fuel burn of a conservative 2T/hr, giving you 3.5h-4h + reserves. Cruises at 0.68-0.70. You would be able to lift 81 males + 9T fuel provided you had over about 1500-1800m runway at those temperatures.
So, if they filled it up to the gills they may have been approaching diversion fuel after 1600NM, but not running out. But then who knows how much they brought with them, or whether they's been able to get to panned cruise level, etc etc etc.
Anyhow, very sad.