The recent bomb attack and shooting massacre in Oslo, Norway killed 92 besides injuring many. This horrifying incident has brought back the memories of the deadly attacks carried out in other parts of Europe in the past decade.
The United States intelligence bureau has been constantly issuing warnings about possible terror attacks in European countries.
In the wake of terror attacks, the U.S. State Department advised its citizens to take extra precaution. Most often, the attacks are conspired with a mastermind and at times the attacks are stray and causal. The greatest worry for the United States is that many Americans are in Europe, living and traveling to various destinations as tourists, businessmen and students.
Start the slide show to revisit some of the terror attacks that debilitated the people in European countries.
Railway workers remove debris from the wreckage of a bombed public train as a second destroyed train is pulled out of Atocha train station in Madrid in this March 12, 2004 file photo. Al Qaeda leader Osama bin Laden was killed May 1, 2011, in a firefight with U.S. forces in Pakistan and his body was recovered, U.S. President Barack Obama said on May 1, 2011. "Justice has been done," Obama said in a dramatic, late-night White House speech announcing the death of the elusive mastermind of the Sept. 11, 2001, attacks on New York and Washington that killed nearly 3,000 people. REUTERS/Kai Pfaffenbach/FilesA video grab image shows debris from a damaged bus in Tavistock Square, following a bomb blast on July 7, 2005, taken from handout footage released in London on October 12, 2010. The inquests into the deaths of 52 people killed in the London suicide bombings of July 7, 2005, are being held at the High Court, with the focus on whether the attacks on the capital's transport system could have been prevented. REUTERS/London Bombing InquestTurkish police officers examine the scene in front of the Neve Shalom Synagogue after a suicide bomb attack in Istanbul November 15, 2003. At least 17 people were killed and more than 200 wounded on Saturday when car bombers shattered two Istanbul synagogues as worshippers celebrated the Sabbath. REUTERS/STR NewEmergency workers survey the scene of a metro train collision between two trains in Barcelona, October 31, 2004. Two metro trains collided in the outskirts of Barcelona on Sunday injuring 52 passengers and trapping one of the drivers inside the wreckage, a city council spokeswoman said. The cause of the accident was not immediately known. A train carrying around 100 passengers hit another as it emerged from an engine shed in Vall d'Hebron station at 1230 GMT. REUTERS/Albert Gea PH/AAAbdullah Ahmed Ali (L-R), Assad Sarwar and Tanvir Hussain are seen in this undated handout file photograph in London. Britons Ali, Sarwar & Hussain were found guilty on September 7, 2009 of plotting to kill "thousands" by blowing up transatlantic airliners bound for North America in mid-flight suicide attacks using bombs made from liquid explosives. REUTERS/Metropolitan Police/HaBritish police officers guard an internet cafe in Manchester, northern England April 9, 2009. Britain's most senior counter-terrorism officer Bob Quick quit on Thursday after his security blunder forced police to bring forward a major operation to thwart a suspected al Qaeda plot. Quick was photographed openly carrying a secret document and hours later, police arrested 12 men in unusual daylight counter-terrorism raids across northwest England. Officers also searched eight addresses in Manchester, Liverpool and Lancashire. REUTERS/Darren StaplesA man identified in U.S. court papers as Richard Reid, 28, is shown in this December, 2001 police photograph. Reid, suspected of trying to blow up a Paris-to-Miami flight by detonating explosives packed into his shoes, was ordered held in jail December 24, 2001 as police in three countries tried to determine who he was and how he managed to get the makeshift bombs aboard the plane. He was arrested December 22 after a flight attendant on American Airlines Flight 63 caught him lighting a match and allegedly trying to ignite his explosives-stuffed shoes. Britain's Scotland Yard said Reid is believed to be British while French officials have been quoted saying he is a Sri Lankan Muslim named Tariq Raja using a false British passport. Newspaper reports have said he may also have used the name Abdel Rahim. REUTERS/Plymouth County Jail/H
