Survivors from a boat which capsized off the Egyptian coast on 21 September have told the BBC that hundreds of people may have drowned.
The boat was carrying about 550 migrants when it capsized eight miles (12km) off the coast, they say. Authorities have rescued 163 people and recovered 42 bodies so far off the port city of Rosetta.
Four suspected traffickers have been detained, according to the AFP news agency. They are accused of involuntary manslaughter and human trafficking, judicial officials were reported as saying.
The incident came after the EU's border agency warned that increasing numbers of Europe-bound migrants are using Egypt as a departure point.