A French government source said Thursday that children and pregnant women were among the at least 27 migrants who perished after their tiny boat sunk while attempting to cross the English Channel.

Gerald Darmanin, the Interior Minister, also reported the arrest of a fifth accused human trafficker suspected of being engaged in the deadliest migrant catastrophe on the perilous sea channel to date.

French officials reported somewhat different estimations for the number of deceased in their early response to the disaster, ranging from 27 to 31. Darmanin used the number 27 on Thursday.

Authorities are seeking to establish the nationalities of the victims of Wednesday’s sinking, according to Darmanin. Hypothermia was addressed in two of the survivors. Darmanin revealed on RTL radio that one is Iraqi and the other is Somali.

“Pregnant women and children perished,” he claimed, although he didn’t say how many.

Darmanin had previously reported the arrest of four alleged drug dealers on suspicion of being connected to the sunken boat on Wednesday. A fifth suspected trafficker was apprehended overnight, he told RTL.