French police broke twin sieges linked to Wednesday’s Charlie Hebdo killings with simultaneous assaults yesterday.

The double attacks were timed to minimise risk to hostages held at both sites but had starkly different results.

Loud bangs and smoke, apparently from stun grenades, heralded the assault on a print works on an industrial estate in the small town of Dammarten en Goele near the Charles de Gaulle airport.

Police had surrounded the works to capture brothers Said and Cherif Kouachi, who stormed the Charlie Hebdo magazine in Paris on Wednesday, killing 12 people.

A police spokesman confirmed that both brothers were killed in the assault and their sole hostage, an employee at the works, was safe and unharmed.

At the same time, a twin assault was carried out in the east of Paris in the Porte de Vincennes area, where at least six people, reportedly including children, had been taken hostage at a kosher supermarket.

Hostage-taker Amedy Coulibaly was killed in the assault and reports said that two police were wounded. At least four hostages were killed.

It is thought he was the shooter who killed trainee policewoman Clarissa Jean-Philippe in Montrouge, Paris, on Thursday.

French police had released pictures of a man and a woman linked to the killing, saying they were armed and dangerous.

They were named as Mr Coulibaly and Hayat Boumeddiene.

Mr Coulibaly had demanded that the Kouachi brothers be set free and threatened that, if the print works in which they were encircled was stormed, he would kill his hostages.

It was this threat that prompted the simultaneous assaults.

There was no news of Ms Boumeddiene.

The sieges had paralysed the areas in which they occurred.

The small town of Dammarten en Goele came to a shuddering halt.

Residents were told to stay at home, hundreds of people were locked inside office buildings and several schools were evacuated.

In Paris, kosher restaurants were shut across the capital and the shops and cafes in the famed Marais Jewish neighbourhood were ordered to close.

Schools in the Porte de Vincennes area were on lockdown and two Metro stations were closed.