"The conflict in the Middle East has led to an absolutely unacceptable increase in anti-Semitism and insecurity for Jews in Denmark," Justice Minister Peter Hummelgaard said.

"We're in a situation where the terrorist threat hanging over Denmark is serious."

The defence ministry said the Gaza conflict was taking a heavy toll on police resources, with several protests being held at a time when Coran burnings by anti-immigrant groups have stoked tensions.

"In this context... armed forces will support the surveillance of Jewish and Israeli sites in Copenhagen," such as synagogues or the Israeli embassy, it said.

The deployment will begin December 6.

The country counts an estimated 6,000 to 8,000 Jews, according to the independent Utrikespolitiska research institute.

Contacted by AFP, the defence ministry declined to say if similar protective measures would be taken for Muslim sites in the country.

The war in the Middle East broke out when Hamas militants burst through Gaza's militarised border into Israel on October 7 and killed about 1,200 people, mostly civilians, while also taking around 240 hostages, according to Israeli authorities.

More than 15,200 people have since been killed in the besieged Palestinian territory, according to Hamas, in more than eight weeks of combat and heavy bombardment.