Masked men have robbed two Qatari women and their driver on a motorway north of Paris, taking valuables worth €5m (£4.5m; $5.6m), police sources say.
The sisters had just left Le Bourget airport in their Bentley on Monday evening when they were forced off the road and sprayed with tear gas.
"Everything in the vehicle: jewels, clothes, luggage" was taken, a police source told AFP news agency.
A Saudi prince was robbed while passing through the same area two years ago.
Le Bourget bills itself as "Europe's premier business airport".
A source who spoke to French digital TV station BFMTV said the women's car had been forced to stop near a service station.
The section of the motorway where the robbery took place is favoured by criminals targeting luxury cars or wealthy-looking foreigners stuck in traffic jams:
- In April last year, an east Asian art collector was robbed of jewels worth €4m when three people caved in the window of her taxi
- In August 2014, heavily armed men attacked a convoy of cars belonging to a Saudi prince, stealing €250,000, as he headed in a convoy to Le Bourget
Last month, US reality TV star Kim Kardashian was tied up and robbed at gunpoint of jewellery worth up to €6m in a luxury apartment in the heart of Paris.
Earlier this month, the French government announced extra funding for the tourist industry, promising to install more surveillance cameras in areas of the capital targeted by robbers.