PARIS (AFP) - French President Francois Hollande made an unannounced visit to the main mosque in Paris yesterday, a year since 1.5 million people thronged the French capital in a show of unity after attacks on the Charlie Hebdo newspaper and a Jewish supermarket.

Mosques across France opened their doors to the public over the weekend in a bid by the Muslim community to build bridges, following the series of terror attacks that rocked France last year.

"The President had a short conversation and a moment of friendship and fraternity over a cup of tea," a French presidency official said.

Earlier, Mr Hollande attended a low-key event at Place de la Republique to mark the huge march in Paris on Jan 11 last year, which was attended by several world leaders including German Chancellor Angela Merkel and Israeli Prime Minister Benjamin Netanyahu.

He unveiled a plaque next to an oak tree planted in the square in memory of the victims of last year's militant attacks.

Several thousand people gathered for the event. Veteran rocker Johnny Hallyday performed a short song and the army's choir gave a rousing rendition of the Marseillaise.

Twelve people were killed in the Jan 7 assault last year on Charlie Hebdo, which had been in the militants' sights since publishing cartoons of the Prophet Muhammad in 2006.

The next day, another extremist shot dead a policewoman before killing four people in a siege at a Jewish supermarket.

France's year of militant bloodshed culminated in the coordinated shootings and suicide bombings in Paris on Nov 13 that killed 130 people and were claimed by the Islamic State in Iraq and Syria. The attacks left the country in shock and under stringent security measures, including a state of emergency.

One of those who attended the commemoration yesterday, Mr Jacques Clayeux, 54, had known one of the murdered cartoonists.

"Everyone grew up with those guys," he said.

"But I have mixed feelings today. It is terrible to attack journalists, but it's scary to live under a state of emergency."