A trial began Tuesday in Germany for four alleged members of U.S.-designated terror group Hamas who are suspected of organizing weapons caches across Europe.

The country's top prosecutor accuses the men of membership in a foreign terrorist organization. It's a pilot case for prosecutors, German news agency dpa reported.

"For the first time in Germany, people are facing charges of participating as members of the foreign terrorist organization Hamas," prosecutor Jochen Weingarten said, according to dpa.

The men are accused of seeking out some weapons depots set up years ago, as well as setting up new ones, for Hamas across Europe so it could later use the firearms and ammunition for attacks against Israeli and Jewish targets on the continent, prosecutors said when filing charges last year.

The weapons were allegedly moved around Europe in preparation for Hamas' terror attack against Israel on Oct. 7, 2023, prosecutors said. Around 1,200 people, mostly civilians, were killed in that attack, and about 250 taken hostage.

The attack triggered Israel's air and ground offensive in Gaza, which has killed more than 48,200 Palestinians, according to Gaza's Health Ministry, which doesn't distinguish between combatants and civilians. The ministry says more than half the dead have been women and children.

Hamas also considered targeting the Israeli Embassy in Berlin, the area around Tempelhof Airport in the capital and the U.S. Ramstein Air Base in Germany, authorities said.

Abdelhamid Al A., Mohamed B., Nazih R. and Ibrahim El-R. were arrested in December 2023. Prosecutors identified them only by their first name and last initial in line with German privacy laws.

All four had important positions within Hamas, prosecutors asserted.

The men allegedly set up a weapons cache in Bulgaria in 2019 and in Denmark later that year. They sought to find a spot in Poland but were unsuccessful, prosecutors said.