4. How dangerous is the journey?
According to the IOM, more than 3,770 migrants were reported to have died trying to cross the Mediterranean in 2015.
Most died on the crossing from north Africa to Italy, and more than 800 died in the Aegean crossing from Turkey to Greece.
The summer months are usually when most fatalities occur as it is the busiest time for migrants attempting to reach Europe.
which saw a boat carrying about 800 people capsize in the sea off Libya. Overcrowding is thought to have been one of the reasons for the disaster.