Eighteen people have been evacuated from a shopping centre north of Paris, after up to three armed men entered the building early on Monday.
A police source said they had been hiding in a canteen in the Qwartz centre in Villeneuve-la-Garenne.
It was unclear whether anyone else was still trapped in the centre or whether any hostages had been taken.
Police said the incident appeared to be an armed robbery, not a terrorist attack.
“At around 06:30 (04:30 GMT), two or three armed criminals went into the Primark store for what we think was initially an attempt at armed robbery,” a police source, who wished to remain anonymous, is quoted as saying by AFP news agency.
Traffic in the area was stopped and all other shops nearby were closed.