The information about the arrest came from Marijan Banelli, president of the Croatian Association of Hauliers.
The ministry has contacted the US side in Iraq through diplomatic channels, but was unable to confirm the drivers' identity or their citizenship.
Ministry spokeswoman Ivana Grgic said that no employer or anyone else had officially contacted or sought help from the ministry.
The ministry is working on the case and expects to obtain more information on Wednesday, she said.
Jutarnji List daily carried unconfirmed reports in its Wednesday edition saying that three persons holding Croatian passports have been detained for some time in Iraq.
Benelli told the daily that according to his information, the arrested hauliers were of Serb nationality and that they probably possessed Croatian passports.
He added that there were some 30 Croatian hauliers in Iraq at the moment.