At least 43 migrants are missing after a boat heading towards Europe capsized near the Tunisian coast, a Tunisian Red Crescent official said Saturday. 

What do we know so far?

Red Crescent official Munji Salim said the boat carrying 127 migrants sank near the southeastern Tunisian city of Zarzis late Friday. So far, 84 migrants have been rescued by authorities, with 43 having disappeared. 

The rescued migrants were transferred to Zarzis port. "The sheltering centers in southern Tunisia are crowded with migrants," Salim said.

The boat had departed to Europe from the northwestern Libyan port city of Zuwara earlier this week. 

The Tunisian Defense Ministry said the nationalities of the rescued include 46 Sudanese nationals, 16 Eritreans, 12 Bangladeshis and five from Egypt. 

The ministry said the migrants were between the ages of three and 40.

Why are the migrants heading to Europe?

Many of the migrants taking off to Europe depart from either Libya or Tunisia.

The asylum seekers are often fleeing from war, authoritarianism and terrorism from various parts of Africa, with some migrants also leaving their home countries due to poor economic conditions.

The migrants frequently travel on unseaworthy wooden boats and rubber dinghies. Some migrants pay a human smuggler to help them make the dangerous journey. 

More than 550 people have died this year while making the journey to Europe, according to the International Organization for Migration (IOM).

The Tunisian coast guard last month saved 267 migrants drowning in the Mediterranean after their boat capsized. Those migrants also embarked on their journey from the Libyan coast. 

The migrants sometimes face danger from coastal authorities. 

German NGO Sea-Watch this week filmed the Libyan coast guard chasing a migrant boat and shooting in its direction. The NGO called on EU authorities to stop cooperating with the Libyan coast guard in dealing with the migrants. 

wd/mm (AFP, dpa)