The four Syrian nationals aged between 30 and 41 have been accused of "causing the death of more than one person" and "trafficking migrants," the Dogan news agency reported on Thursday.
Twelve migrants drowned on Wednesday when two boats sank in Turkish waters. Attention focused on the toddler Aylan Kurdi, whose tiny body was photographed washed up on a beach in the Turkish resort of Bodrum. His death dominated headlines across Europe and went global on social media.
Aylan's four-year-old brother Ghaleb and their mother Rihana also drowned when their boat sank. Aylan's father, Abdullah (photo), was found semi-conscious and taken to hospital near Bodrum, according to Turkey's Sabah newspaper.
The boy's aunt, who lives in Canada, said the family's refugee application was rejected by Canadian authorities in June. According to her statement, this was why the Kurdish family from Syria embarked on the deadly boat journey across the Mediterranean Sea. Only the father of the two boys survived.
Erdogan: 'Humanity drowning in the Mediterranean'
Meanwhile, Turkish President Recep Tayyip Erdogan accused Europe of having turned the Mediterranean Sea into a "graveyard" for refugees. He said on Thursday: "It is humanity that is drowning in the Mediterranean."
Over the last weeks, there has been a dramatic surge in the numbers of migrants - mainly from Syria, Afghanistan, Pakistan and several African countries - leaving Turkey by sea for Greece in the hope of a new life in Europe.
Turkish Prime Minister Ahmed Davutoglu said in a statement on Thursday that his country would continue to keep its doors open to refugees. He urged European countries to take their share of the burden.
Turkey has already taken in about two million refugees from neighboring Syria.
das/jm (AFP, Reuters, dpa)