French authorities are hunting four thieves for Sunday's brazen heist at the Louvre where they seized eight priceless and historical pieces of jewellery, Paris's chief prosecutor said.
The four men were a "strike team" who robbed the Louvre's Apollo Gallery containing France's crown jewels, wearing masks to hide their faces and using high-powered scooters to escape prosecutor Laure Beccuau, told BFMTV television.
She said the thieves threatened museum guards with the angle grinders they used to cut into the glass display booths containing the jewels they were after.
The gang drove a truck towing an extendable power ladder, commonly used to lift furniture into buildings, to the side of the Louvre to gain access through a window they broke, said Beccuau.
The Louvre's alarms were functioning at the time, she added, but there "remains the question of whether the guards heard the alarm" and whether the alarm sounded in the gallery where the theft was taking place, she said.
The prosecutor said their working theory was that the heist team was working under orders for a criminal organisation.
"Organised criminal gangs can have two aims: either to fulfil an order placed with them, or to acquire gems for money-laundering ends," she said.
Beccuau said around 60 investigators were working on the high-profile case.
A yellow vest used by one of the culprits has already been recovered, she added.
"I have no doubt that (the museum) will be able to recover" the stolen items "in the coming days", she said.