German officials say three suspected al-Qaida members arrested on Friday had been planning a bomb attack in the country.
Prosecutor Rainer Griesbaum told a news conference Saturday that the trio had planned to attack a crowded place but had not yet picked a target. He said they were still in the experimentation stage.
Authorities said they decided to arrest the three when surveillance indicated they were pursuing making a detonator, a sign they might be close to carrying out an attack. The suspects had reportedly discussed planting the bomb on a bus.
The three men, all from Morocco, were taken into custody Friday in the western German cities of Duesseldorf and Bochum.
The main suspect, a 29-year-old Moroccan citizen identified as Abdeladim El-K., has been charged with membership in a foreign terrorist organization. Officials say he trained last year in an al-Qaida camp in the Pakistani region of Waziristan near the Afghan border.
The other suspects are a 31-year-old and a 19-year-old.
Police arrested the men on suspicion of planning a terrorist attack and said they posed a "concrete and imminent danger" to the country.
In a statement, Interior Minister Hans-Peter Friedrich said the incident proves that Germany remains a target of international terrorists.
Germany had previously received information that al-Qaida may have been planning a "Mumbai-style" attack in the country later this year - a reference to the 2008 terrorist siege in India's financial capital in which 166 were killed.
Officials said the three suspects had praised Thursday's deadly bomb attack on a cafe in Marrakech, Morocco.
Moroccan officials say the bombing appears to be the work of al-Qaida.
Some information for this report was provided by AP, AFP and Reuters.