German police foil plot to unleash 'massive' attack on US military base

Germany said yesterday it had arrested three Islamic militants suspected of planning "imminent" and "massive" bomb attacks on Frankfurt's international airport and a nearby US military base, preventing what would have been the most devastating terrorist attack on an American target since 11 September 2001.

Monika Harms, the federal prosecutor, said the three men – two of whom were German converts to Islam – were caught at a "bomb-making" factory in a holiday apartment in the village of Oberschledorn, near the central town of Kassel. She claimed they had enough chemicals to produce an explosion equivalent to 550kg of TNT. "We succeeded in recognising and preventing serious and massive bomb attacks," Ms Harms added.

Officials at the Federal Criminal Bureau said the chemicals, which included 730kg of hydrogen peroxide, could have produced bombs bigger than those detonated in the London and Madrid terror attacks.

The Chancellor, Angela Merkel, congratulated the country's security services, saying their actions deserved "praise, recognition and respect". Franz Josef Jung, the Defence Minister, described the threat as "imminent" and said the group appeared to have been preparing to mount an attack, using either car bombs or suicide belts, over the coming days – perhaps to coincide with the anniversary of 9/11.

As is customary in Germany, the three suspects were identified only by their first names and last initials. Fritz G, a 28-year-old German from Ulm in Bavaria, described as the leader of the group, had recently converted to Islam. Also arrested were Daniel S, aged 22, another German convert to Islam, from the Saarland, and Adem Y, a 29-year-old Turkish citizen from the German state of Hessen. All three were said to be members of the Jihad Union, a group linked to al-Qaida, and reportedly set up the German cell of the group. The Jihad Union is a Sunni Muslim group, based in central Asia, which carried out a terror attack in Uzbekistan in 2006 and is now active in Pakistan. The suspects were said to have trained at Jihad Union camps in Pakistan.

Germany's elite anti-terrorist police squad, the GSG9, raided the group's rented holiday home on Tuesday afternoon and seized two of the suspects immediately. One escaped through a bathroom window but was caught minutes later. During scuffles, a shot was fired and a police officer was slightly hurt.

Television news footage showed Fritz G – a young man with long, dark hair and wearing dark blue military-style fatigues – being restrained by masked police armed with machine-guns. Police also released photographs of a stack of 12 blue plastic containers that were said to have contained the potentially lethal hydrogen peroxide. Officers said they decided to intervene because the chemicals had a half-life which rendered them effective as bomb-making equipment for only a limited period. "A bomb attack was imminent. It was only a matter of time," said a police spokesman. "Their aim was clear. They wanted to cause an explosion that would kill as many people as possible." Officers searched 40 other properties across Germany.

The suspects apparently first attracted police attention last year, when Fritz G was observed several times as he drove around a US military base near the town of Hanau. Police said they opened a formal investigation into the group earlier this year and the three men must have been aware they were being watched. "The fact they were still prepared to carry on shows just how determined they are," one police official said last night. "They were clearly prepared to die while carrying out their attacks." Police said the group appeared to have selected Frankfurt international airport, Europe's third-busiest hub, for their attack. Another target was the US Air Force base at nearby Ramstein, which acts as the main military airport for American forces in Europe and is the main transit point for injured troops flown out from Iraq and Afghanistan.

Since the start of this year, Chancellor Merkel's government has repeatedly warned that Germany faces the real threat of a terror attack. Ministers have sparked controversy by demanding increased powers of internet surveillance for the police and intelligence services. There was speculation yesterday that police monitoring of the Jihad Union prompted the government warnings.

Germany, which opposed the Iraq war, has to date been spared major attacks such as the bombings in Madrid and London, but some of its peace-keeping troops in Afghanistan have been attacked and killed. In July 2006, police found two unexploded bombs on German commuter trains. Several suspects are on trial in Lebanon, and a Lebanese citizen has been charged in Germany.

Wolfgang Schäuble, the Interior Minister, said that Tuesday's arrests proved conclusively that Germany was as liable as any other European country to be targeted by terrorists.