Belgian flag flies at half mast above the Royal Palace in Brussels on March 22, 2016 in the wake of co-ordinated attacks claimed by Islamic State group (IS) millitants at the city's airport and in a Metro train.  
Belgium will hold three days of national mourning in the wake of the deadly attacks in the capital Brussels that killed around 35 people. 'All national flags on public buildings will be at half-mast,' Frederic Cauderlier, spokesman for Belgian premier Charles Michel, told AFP.
 / AFP / BELGA / NICOLAS MAETERLINCK / Belgium OUT        (Photo credit should read NICOLAS MAETERLINCK/AFP/Getty Images)