Versailles, France - Another day, another emergency evacuation at the Palace of Versailles. Saturday's evacuation after a bomb threat – which turned out to be false – was the sixth one in a week.

"For security reasons, the Palace of Versailles is evacuating visitors and will reopen as soon as the checks have been completed. Thank you for your understanding," the great former royal residence outside Paris said Saturday in a now all-too-familiar message.

The situation is now starting to agitate not just tourists but also local officials and tourism sector players, who see the risk of a key income source dwindling.

France upped its attack alert level in the wake of a fatal stabbing of a schoolteacher earlier this month by a man who claimed the act in the name of the Islamic State extremist group.

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The attack in the northern city of Arras also came amid heightened concern over security after the attack by Palestinian militant group Hamas against Israel which has been followed by retaliatory air strikes on the Gaza Strip.

Against this background, France has been plagued by false bomb threats not just against the Palace of Versailles but also the Louvre Museum and a host of regional airports just as fall holidays are underway.

There were some 5,000 people inside the palace at the time of Saturday's evacuation, said a police source. The palace reopened later in the day following checks.