France has paid homage to four Jewish hostages killed at a kosher supermarket in Paris - a year after a spate of jihadist attacks that began with a deadly assault on the Charlie Hebdo weekly.

Tributes were also paid to Clarissa Jean-Philippe, a young policewoman who was also killed by the gunman who went on to carry out the supermarket siege, with President Francois Hollande unveiling a plaque in her honour in the Paris suburb of Montrouge where she died.

A total of 17 people were killed in the January 2015 attacks which rocked France and set off a wave of Islamist violence that reached a head in November when a group of gunmen and suicide bombers killed 130 people in Paris.

The 26-year-old policewoman was killed on January 8 by Amedy Coulibaly, the gunman who went on to attack the Hyper Cacher supermarket in east Paris.

Three shoppers and an employee were killed by Coulibaly before he was killed in a police raid.

"Despite continuing traumatic feelings, life has returned to normal with a renewed sense of fraternity," said Haim Korsia, France's grand rabbi.

Also this weekend, mosques around France opened their doors to visitors in a move to "highlight the real values of Islam, to set straight the cliches about links to violence and terrorism," Anouar Kbibech, head of the French Council of the Muslim Faith, said.

Commemorations will culminate in a public event tomorrow in the Place de la Republique, the vast square that became the rallying point for the 'Je Suis Charlie' solidarity movement, and for similar movements after the deadly November 13 attacks.

There, a 10-metre (35-ft) oak will be planted as a "tree of remembrance".

Meanwhile, German police raided an asylum seeker shelter where they said the man who sought to attack a Paris police station on Thursday had lived.

Police found no indications that other attacks had been planned, they said in a statement following the search at the shelter in western Germany's Recklinghausen.

The police statement did not specify that he was an asylum seeker but a source close to the matter said the man was indeed registered as one.

The man was shot dead by police after trying to storm a police station in northern Paris on Thursday, brandishing a meat cleaver and wearing a fake suicide vest.

The attempted attack took place exactly one year since the Charlie Hebdo terror attacks.