The suspect, an "alleged follower of a radical Islamic ideology", was arrested on Thursday on charges of planning "a serious act of violence endangering the state".

The man had acquired two heavy knives "around 40 centimetres (more than one foot) in length" in recent days, prosecutors in Munich said.

He planned to "attack Bundeswehr soldiers" in the city of Hof in northern Bavaria during their lunch break, aiming "to kill as many of them as possible", prosecutors said.

"The accused wanted to attract attention and create a feeling of insecurity among the population," they said.

German security services have been on high alert over the threat of Islamist attacks, in particular since the Gaza war erupted on October 7 with the Hamas attacks on Israel.

Police shot dead a man in Munich this month after he opened fire on officers in what was being treated as a suspected "terrorist attack" on the Israeli consulate in Munich.

The shootout fell on the anniversary of the kidnap and killing of Israeli athletes at the 1972 Munich Olympic Games by Palestinian militants.

The 18-year-old suspect had previously been investigated by authorities in his home country Austria on suspicion of links to terrorism but the case had been dropped.

The incident capped a string of attacks in Germany, which have stirred a sense of insecurity in Germany and fed a bitter debate of immigration.

Three people were killed last month in a suspected Islamist stabbing at a festival in the western city of Solingen.

The suspect in the attack, which was claimed by the Islamic State group, was a Syrian man who had been slated for deportation from Germany.

A federal interior ministry spokesman said if an Islamist motive was confirmed in the latest foiled attack, it would be "further evidence of the high threat posed by Islamist terrorism in Germany, which was recently demonstrated by the serious crimes in Mannheim and the attack in Solingen, but also by acts that were fortunately prevented by the timely intervention of the security authorities".

The Solingen stabbing followed a knife attack in the city of Mannheim in May, which left a policeman dead, and which had also been linked to Islamism by officials.

Germany has responded to the attacks by taking steps to tighten immigration controls and knife laws.

The government has announced new checks along all of its borders and promised to speed up deportations of migrants who have no right to stay in Germany.

The number of people considered Islamist extremists in Germany fell slightly from 27,480 in 2022 to 27,200 last year, according to a report from the federal domestic intelligence agency.

But Interior Minister Nancy Faeser warned in August that "the threat posed by Islamist terrorism remains high".