The theft took place on Thursday, March 9th at around 8pm, reported Le Parisien newspaper.
According to reports the Americans were in possession of a large quantity of jewels and diamonds and were approached by two men as they returned to their car underneath the Place Vendôme, which is the city's hub for luxury jewellers.
The robbers stripped the American shoppers of the diamonds and other jewels before fleeing.
It is not known if the victims were hurt in the robbery.
Paris’s crime squad has been placed in charge of the investigation.
The robbery is just the latest high-profile theft in the French capital in recent weeks, following the armed attack on Kim Kardashian in January.
Kardashian was robbed of some €10 million worth of jewels at a private residence near the Madeleine church, not far from Place Vendôme.
It comes after numerous other high profile robberies that have targeted members of the Saudi royal family and visitors from China.
The Kardashian robbery in particular was a blow to Paris’s global image.
Centre-right one-time presidential hopeful Nathalie Kosciusko-Morizet (NKM) said the robbery demonstrated “the general emergency around security” in Paris.
For NKM, urgent measures need to be taken to protect the image of Paris as a safe place for all tourists, including the mega-rich.
“There is a general emergency around security in Paris,” she said. “The powers that be and the City Hall are not reactive enough.”
She said the story would only harm the image of Paris as a destination for tourists.
Of course the vast majority of visitors to Paris are extremely unlikely to be the victim of the kind of robbery experienced by Kardashian.
A point made by mayor Anne Hidalgo.
Hitting back at criticism of security in Paris, Hidalgo stressed the attack on Kim Kardashian was a “very rare act, occurring in a private area” which “does not call into question the safety in public areas of Paris.”