Adama Barrow says probe launched as nation mourns 'national disaster' that saw dozens of people drowning off Mauritania.
Gambia's President is vowing to punish people traffickers after dozens of Gambians died in a shipwreck off Mauritania's coast.
They were trying to reach Spain's Canary Islands.
At least 85 people survived and were brought ashore
Al Jazeera's Mohamed Vall reports from northwestern Mauritania.