Both have been on the U.S. State Department's list of terrorist groups.
German Interior Minister Wolfgang Schaeuble told journalists on September 5 in Berlin that members of the Islamic Jihad Union (IJU) had planned "very major" attacks in Germany.
"This Islamic Jihad Union, which obviously works very closely with the network from Al-Qaeda, has not only prepared attacks against Germans in Afghanistan, but very major attacks in our country," he said. "According to what we know from our [security services], if the suspects had carried out their plans the scale of these attacks would have been considerable."
"It would be strange to link [the German plot] to a Central Asian group because [IJU members] have been very domestically based and they have not been active in international terrorism in that way."
Schaeuble's statement came after German police arrested three men on September 4 on suspicion of plotting to bomb military and civilian airports, restaurants, and discotheques.
Schaeuble said the three -- two had German passports and another Turkish citizenship -- had planned the attacks on the orders of an international terrorist network.
German Prosecutor-General Monika Harms said the IJU is made up of Sunni Muslims mainly active in Central Asia but it has expanded to other parts of the world, including Europe. She said it had established a cell in Germany, the German news agency dpa reported on September 5.
The IJU, also referred to as the Islamic Jihad Group, is an obscure group first mentioned in 2004 after bomb attacks in the Uzbek cities of Tashkent and Bukhara that left 47 people dead in March and April 2004.
Uzbek authorities at the time accused other banned groups -- including the IMU and Hizb ut-Tahrir -- of plotting the attacks.
But the IJU claimed responsibility for the attacks (the statement was apparently received via e-mail and was published on stopdictatorkarimov.com).
The IJU's name reemerged again in July 2004 when a string of bombings hit the U.S. and Israeli embassies in Tashkent as well as the office of the Uzbek prosecutor-general. The attacks left two dead and several wounded.
Following the attacks, the U.S. State Department decided to categorize the IJU as a "Specially Designated Global Terrorist" group.
An online database (MIPT Terrorism Knowledge Base) says the group is an offspring of the IMU, something that Harms also noted.
The IMU targets authoritarian regimes in Central Asia and says it wants to establish an Islamic state in their place.
IMU Under Attack
Militants from Uzbekistan and other Central Asian countries moved to Afghanistan and then to Pakistan in the 1990s to escape a crackdown against them at home.
The IMU's core is believed to have been destroyed during the U.S.-led bombings of terrorist camps in Afghanistan following the September 11, 2001 attacks in the United States.
The remaining members of the IMU are believed to be hiding in border areas between Afghanistan and Pakistan.
The IJU has not publicly announced its goals or philosophy. It has not claimed responsibility for any other attacks since 2004, including the recent foiled plot in Germany.
But the Islamic Jihad Union's suspected involvement in the plot in Germany comes as no surprise to some security analysts.
One of them is Colonel Nick Pratt, a CIA veteran and a head of the Program on Terrorism and Security at the George C. Marshall European Center for Security Studies in Germany.
"First and foremost, it does not come as any surprise," he said. "These people are part of this network of Al-Qaeda's affiliate movements and they are doing exactly what the groups did in the Netherlands, in Spain, in London. [Germany is] where they can operate. They know this place, they know the area. "
Pratt says the IJU recruited people in Germany and then radicalized them at an Islamic center.
German officials said one of the men arrested had links to a mosque in Neu-Ulm, in southern Germany. The country's police have suspected for several years that the mosque has been used as a base for extremists planning attacks.
Harms said the men attended a training camp in Pakistan in 2006. However, some experts question the IJU's involvement in the German plot.
Matthew Clements is the Eurasia editor of the London-based Jane's Information Group.
Doubting The IJU's Existence
"It would be strange to link [the German plot] to a Central Asian group because they have been very domestically based and they have not been active in international terrorism in that way," he said.
Some experts have questioned the very existence of the group in the past. They have said the IJU is a mere disinformation tactic used by the Uzbek government to justify its repression against Muslims.
Craig Murray, the former British ambassador to Uzbekistan, writes on his website that the evidence that this organization exists at all is "extremely tenuous and if it does it is almost certainly the fruit of an Uzbek agent provocateur operation."
In October 2005, the British Parliament discussed identifying the IJU as a banned terrorist organization. A member of parliament, Hazel Anne Blears, testified before the British House of Commons that the group poses a threat to the country's interests abroad.
Other parliament deputies questioned Blears' testimony. British parliamentarian Adam Price said that peaceful Uzbek civilians at Andijon "were killed not by the Islamic Jihad Union but by the brutality of the Karimov regime that it is trying to overthrow."
(RFE/RL's Uzbek Service contributed to this report.)