Visitors to the Louvre learned by loudspeaker announcement of this morning's attempted attack on the Paris museum and there was no panic, witnesses said, though some children cried as guards directed people to sit tight together and away from windows.

A French soldier shot and wounded a man armed with a machete and carrying two bags on his back as he tried to enter the world-renowned museum in what the government said appeared to have been a terrorist attack. 

READ: Machete-wielding attacker shot outside the Louvre

The man, who police said had shouted "Allahu akbar" (God is greatest) as he rushed toward the museum, remains alive but seriously wounded. His bags contained no explosives.

"(The announcement) came over the loudspeakers that are dotted around," said Paul Lecher, 68, a retired Parisian and frequent Louvre visitor.

"Everything happened calmly," he told Reuters. "It was just a case of listening ... People quickly understood, even those who didn't understand a word of French, that something unusual was happening."

The Louvre, home to Leonardo da Vinci's 'Mona Lisa', ancient Egyptian artefacts and countless other treasures, is a major tourist attraction. Housed in a former royal palace on the banks of the Seine, it welcomed 7.3 million visitors last year.

KEPT AWAY FROM WINDOWS

On Friday about 1,250 visitors were kept inside for a time after the attempted attack, authorities said.

"There were announcements, then the security guards started running all over the place and after a short period they started gathering everybody up and getting them to one side of the building," said Lance Manus, 73, from Albany, New York.

"They pulled the shades, they didn't want anybody to sit by the windows," said Manus, in Paris with his wife Wendy to mark their 50th wedding anniversary. "I guess they were concerned that something would be coming from outside."

French police secure the site near the Louvre Pyramid in Paris. Photo: Reuters/Christian Hartmann

People were calm, but some young children were crying, they said.

"The very young children, the teachers kept them busy playing games," said Wendy Manus. "They were singing and trying to keep the children calm and quiet."

After an hour, they were told to evacuate. The couple said they did not even have time to see the 'Mona Lisa'.

Asked if they had been scared, Lance Manus said: "We come from the US, we have our scares just like you have."

A couple of Czech tourists, Azra and Resip, praised the professionalism of the security guards.

"They organised everything properly," Azra said.

"Don't give those guys too much attention," her friend Resip said, referring to the attacker.

France has been hit by a series of militant Islamist attacks over the past two years in which more than 230 people have been killed. The soldier who fired at the machete-wielding man was from one of the patrolling groups that have become a common sight around Paris since a state of emergency was declared across France in November 2015. It remains in force.

A spokeswoman said the Louvre remained closed in afternoon and could not say when it would reopen.