Japan issued a travel alert for Europe on Monday, joining the United States and Britain in warning of a possible terrorist... (Associated Press) 
 
 The sky is blue behind the TV tower in Berlin, Germany, Monday, Oct. 4, 2010. Britain's Foreign and Commonwealth Office changed its travel advisory for British citizens in France and Germany from a "substantial" threat of terrorism to a "high" threat, but the office said it does not comment on intelligence matters and thus could not say whether the change was related to the U.S. travel alert. The State Department plans to caution Americans traveling in Europe to be vigilant... (Associated Press) 
 
 French soldiers patrol under the Eiffel Tower in Paris, Sunday, Oct. 3, 2010. The U.S. government has warned its citizens to be vigilant while traveling in Europe because of the threat of an... (Associated Press) 
 
 The attack, part of a recent spike in American drone strikes on Pakistan, came as Germany said it has "concrete evidence" that at least 70 Germans have undergone paramilitary training in Pakistan and Afghanistan, and about a third have returned to Germany. The terror cell said to be behind the Europe plot _ eight Germans and a Briton _ were believed to have been in hiding in the region. A German Foreign Ministry official told CNN Monday that German authorities have been given access to Sidiqi in Afghanistan. Such differences have played out repeatedly in the years since the 9/11 attacks on the United States, they said. On Friday, Sweden raised its threat level from "low" to "elevated," the third-highest threat level on a scale of five that ranges from "no threat" to "low threat" to "elevated threat" to "high threat" to "very high threat."
– An American missile attack has killed at least five German nationals suspected of being part of a terror cell training in Pakistan, Pakistani officials say. The missile hit a house in Waziristan, the region where authorities believe a terror cell training for an attack on Europe was hiding out, the AP reports. Dozens of European militants are believed to be training in the area and it's not clear whether the drone attack is linked to the terror plot that has Europe on alert. European intelligence officials say they believe a terror cell that originated in Hamburg is behind a plot to launch coordinated attacks on city centers, CNN notes. The group, whose members are of assorted ethnic backgrounds including Turkish and Iranian, attended the same Hamburg mosque as 9/11 hijacker Mohamed Atta. The group is believed to have left Hamburg to train in Pakistan early last year, officials say, citing intelligence gained from a German militant captured in Afghanistan in July.