About a dozen migrants may have entered Germany on forged Syrian passports like those used by two Paris suicide bombers, according to a news report Tuesday which authorities did not confirm.

Bild newspaper, citing unnamed government sources, said the passports bore the "same forgery characteristics" as those carried by two men involved in the November 13 France attacks claimed by the "Islamic State" (ISIS) terrorist group, AFP reports.

The passports were stolen blanks issued by the Syrian government, but filled in by forgers with the personal details of people who then joined tens of thousands on the refugee trail to Europe, according to Bild.