The trio, aged from 15 to 16, are “strongly suspected of planning an Islamist-motivated terror attack and of having committed to carrying it out”, prosecutors said in a statement.
All three had also “committed to carrying out a crime – murder and manslaughter”, Duesseldorf prosecutors added.
Investigators did not provide further details on the alleged plot, saying the inquiry was still underway.
Denmark and Germany arrest Hamas suspects planning terror attacks
Denmark and Germany arrest Hamas suspects planning terror attacks
But Germany’s biggest-selling daily Bild reported that the youths were allegedly planning to carry out Molotov cocktail and knife attacks in the name of the Islamic State group.
Their targets are believed to be Christians and police, according to the report, which said the suspects were also weighing whether to obtain firearms.
The country is also particularly nervous about security breaches as it prepares to host the European football championships from mid-June to mid-July.
Police had already foiled a suspected plot earlier this year.
Police in January arrested three people over an alleged attack plot targeting the cathedral in Cologne on New Year’s Eve.
Bild reported that the suspects were Tajiks acting for Islamic State-Khorasan (Isis-K), the same group believed to have been behind March’s deadly massacre in a Moscow concert hall.
“The danger from Islamist terrorism remains acute,” Interior Minister Nancy Faeser said at the time, describing the Khorasan offshoot as “currently the biggest Islamist threat in Germany”.
Islamist extremists have committed several violent attacks in Germany in recent years, the deadliest being a truck rampage at a Berlin Christmas market in December 2016 that killed 12 people.
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Muslims call for expulsion of Swedish ambassadors as tensions rise over Koran burnings
Muslims call for expulsion of Swedish ambassadors as tensions rise over Koran burnings
In October, German prosecutors also charged two Syrian brothers for planning an attack inspired by IS on a church in Sweden.
In December 2022, a Syrian-born Islamist was jailed for 14 years for a knife attack on a train in Bavaria in which four people were injured.
The number of people on the Islamist extremist spectrum in Germany fell from 28,290 in 2021 to 27,480 in 2022, according to a report from the BfV federal domestic intelligence agency.
However, in presenting the report, Faeser said Islamist extremism “remains dangerous”.
Germany became a target for jihadist groups during its involvement in the coalition fighting IS in Iraq and Syria, and its deployment in Afghanistan.