Germany will launch one of its biggest terror trials in decades on Wednesday against four alleged Islamic extremists accused of plotting devastating attacks against US interests. The so-called Sauerland cell was named for a region east where authorities captured the suspects in September 2007 along with 26 detonators and 12 drums of hydrogen peroxide, the substance used in the deadly attacks on London’s transport system two years before. A fourth suspect was extradited from Turkey to Germany in November. Their aim, authorities say, was a deadly bombing “of unimaginable size”, according to chief federal prosecutor Monika Harms, that would also punish Germany for its military presence in Afghanistan. Prosecutors say the four are hardened members of the Islamic Jihad Union, a militant Islamic extremist group with roots in Uzbekistan and ties to al-Qaeda which is believed to have set up training camps for militants along the Pakistan-Afghanistan border. The suspects are accused of planning to car bomb targets including US institutions in Germany and nightclubs popular with Americans.