A duo of thieves have ambushed two diamond dealers on the Paris Metro, seizing a suitcase with €300,000 ($368,000) of precious stones.

Reading like a scene from a crime novel, thieves attacked two Indian men as they returned from a business deal at the 10th arrondissement of Paris on Sunday afternoon, fleeing with a suitcase containing dozens of diamonds.

In what’s thought to be a pre-meditated robbery, the attackers hurled a tear gas canister at the diamond dealers as they were about to exit the turn-stiles at Cadet metro station, according to a report by weekly French political magazine Le Point.

The thieves are still at large, after being “perfectly informed about the route of the two diamond dealers, and preparing their hit perfectly”, Le Point.

The diamond dealers reported the crime to local police, and the case is under investigation by the Paris prosecutor’s office, reports say.

The attack took place less than two kilometres from Paris’ Hôtel de Pourtalès, where thieves held reality TV star Kim Kardashian at gun point, making off with $11 million in jewels, including a $4 million 20-carat diamond engagement ring in October 2016.

The attack on Kardashian was the biggest French diamond heist since 2013, when thieves invaded a diamond exhibition at the Carlton hotel in Cannes, making off with $123 million in jewels.