BERLIN German police boarded a Dutch airliner at Cologne airport on Friday and arrested two men suspected of planning to take part in terrorist attacks.
Officials suspected the men were on their way to a terrorist camp or intended to wage holy war, or jihad, in eastern Africa, security sources told Reuters. They wanted to fly to Uganda from Amsterdam, the sources said.
A police spokesman identified the suspected Islamist militants, on board a KLM aircraft about to take off for Amsterdam, as a 23-year-old Somali and a 24-year-old German born in the Somali capital, Mogadishu.
"It all went off in quite an unspectacular manner," a police spokesman told Reuters television.
Police in the North Rhine-Westphalia region of western Germany said they suspected the men were planning a violent form of jihad and had found farewell letters.
They declined to give further details or to say how they found out about the pair, on the grounds that a criminal case was pending.
Somalia is racked by a civil war between Islamist rebels and the Ethiopian-backed government. A large number of Somali refugees have moved to western Europe in 17 years of conflict.
"The origin of the (suspects) is not surprising because Somalia has for some time been a place where al Qaeda commandos stay and make preparations," said terrorist expert Rolf Tophoven.
Unlike Britain and Spain, Germany has not suffered a serious recent attack on its soil but Germans have been fearful since the northern port of Hamburg was used as a base for planning the September 11 attacks in the United States in 2001.
Officials found documents in the suspects' luggage which pointed to terrorist intentions, security sources said, but police stressed there was no indication the two were about to launch an attack.
"German police authorities removed two passengers from the plane ... All the passengers had to get out for a check of all the luggage, and they removed the suspects' luggage," said a spokesman for KLM.
The flight, KL1804, continued its journey to Amsterdam just over an hour later.
A spokeswoman for the Interior Ministry said there were no firm signs of an attack in Germany.
"We still believe we are caught in the crosshairs of terrorism but there are no indications of concrete preparations for an attack," she told a regular news conference.
Security sources said they were not excluding the possibility that the two men arrested on Friday had loose contacts to a group of people in the western Sauerland region, three of whom were arrested last year.
Authorities believe they were planning attacks against U.S. installations in Germany.
A spokeswoman for the Federal Crime Office said Friday's arrests were unrelated to a search for two suspected Islamist militants which it had announced on Thursday.
The Office had said they believed the two men, one German and one born in Lebanon, might be heading to Germany. They had previously thought they were in Afghanistan.
(Additional reporting by Niklas Mika in Amsterdam)
(Writing by Madeline Chambers; editing by Andrew Dobbie)