Twenty-five former ISIS fighters, women and children, some of them orphaned, returned to Bosnia on Thursday, the Security Ministry said.
Seven men have been handed over to the state prosecutor while six women and 12 children were taken to a reception centre for further examination and medical assistance, the ministry said.
"The suspects are under investigation for the criminal offences of organising a terrorist group, unlawful formation and joining of foreign paramilitary or paramilitary formations and terrorism," the prosecutor’s office said.
"Some of these persons were sought on international arrest warrant by order of the Court of Bosnia and Herzegovina."
Earlier on Thursday, the plane carrying the Bosnian nationals from Syria landed at the airport in the capital of Sarajevo under heavy security. Authorities said they had carried out security checks on the group.
Bosnian officials have said that about 260 Bosnian citizens remain in the camps in Syria, including about 100 men and 160 women and children.
Bosnia has been preparing since October to take back and put on trial nine of its nationals suspected of fighting for ISIS in Syria, but their repatriation has been postponed twice after Turkey invaded the country’s north-east.
In 2014, Bosnia became the first country in Europe to introduce prison terms for its citizens who fought abroad.
Fighters who have since returned to the country were tried and, in most cases, sentenced to prison.
Bosnia's state court has tried and convicted 46 people who returned from Syria or Iraq over the past few years.
ISIS lost its last territorial foothold in Syria in March this year and many of its militants are now believed to be in Kurdish-run prisons in northern Syria.
Hundreds of people are believed to have left Europe to fight for the extremist group in Syria and Iraq, and many are now in detention camps waiting to be handed over to their countries of origin.