One of the Paris attackers reportedly entered into Europe as a Syrian migrant

One of the bombers who carried out the Paris terrorist attacks reportedly entered Europe as a Syrian migrant, according to foreign officials.

French authorities reportedly matched the remains of one of the suicide bombers from the Friday attacks to a Syrian passport that was used to apply for asylum in Europe, according to The Wall Street Journal, which cited unnamed sources.

Politico reports that one attacker came into Europe through Greece with a group of migrants.

A group of seven attackers who broke off into teams of three carried out bombings and shooting attacks across Paris on Friday evening, killing 129 people and injuring more than 300, the Paris prosecutor said Saturday. The terrorist group ISIS (also known as the Islamic State) has claimed responsibility for the attacks.

There have been other reports that a Syrian passport found near one of the attackers was fake. US officials told CBS News that the passport didn't have the correct numbers for a Syrian passport and that the picture didn't match the name.

Migrants traveling through Europe have been known to buy fake Syrian passports on the black market in the Middle East. The Wall Street Journal reported in September that migrants from countries like Iraq and Libya have tried passing themselves off as Syrian because it's easier to get refugee status as a Syrian.

The fake passports are reportedly relatively easy to obtain.

Western officials expressed concern prior to the Paris attacks about terrorists slipping into Europe with large groups of migrants.

BuzzFeed reported last year that smugglers admitted to sneaking ISIS operatives into Europe with groups of refugees. The smuggler, using the pseudonym "Hassan," told BuzzFeed that the jihadis posing as migrants were going to Europe to launch attacks in the West.

"They are waiting for their orders," he said. "Just wait. You will see."