Madrid ( CNN ) -- Inspired by the deadly Columbine school shooting , a Spanish man purchased more than 300 pounds of explosive materials as part of an alleged plan to massacre university students , authorities said Thursday . Instead , Spanish police , who had been tracking him for five months , descended on his home Wednesday morning and arrested the 21-year-old just as he received the potentially deadly materials he had ordered off the Internet , according to authorities . They seized 140 kilograms of the materials . Police arrested the man in Palma de Mallorca , not too far from the University of the Balearic Islands , where they say he planned his attack . Mallorca is one of Spain 's Balearic Islands , off its southeastern coast in the Mediterranean Sea . Police have not released the suspect 's name , but they say he was a student at another educational center where he studied business administration . Although they believe he planned his attack at the University of the Balearic Islands , he had sent a threatening letter to his school , a police statement said . Documents taken from his home , including his personal diary , indicated he wanted to imitate the 1999 U.S. massacre that left 15 dead at a high school in Columbine , Colorado , according to police . `` He showed a hatred for society , especially for university students , and his decision to strategically place pipe bombs filled with shrapnel on the university campus , '' according to the police statement , referring to the documents seized from the suspect 's home . `` He also admitted the hypothesis of suicide while carrying out the massacre , '' the statement added . Police began investigating the suspect five months ago after detecting Internet messages alluding to the Columbine massacre . `` The suspect showed a sympathy '' for the two men who carried out the Columbine attack , the statement said . His blog included sections showing that he knew how to make bombs , displaying the same musical tastes as the Columbine killers , describing his interest in weapons and mentioning `` social isolation that led to situations of feeling left on the sidelines at school , '' the statement said . Read more : Nothing the same after Columbine , say students , teachers . The suspect sought to acquire weapons illegally and later applied for a license to legally possess weapons , a document that is hard to get in Spain . The application was rejected . Police tracked his subsequent efforts to acquire the explosive materials through the Internet before arresting him Wednesday . The suspect `` is not part of any political party or association , '' according to Teresa Palmer , a central government representative in the Balearic Islands . She called it `` a completely isolated event '' and encouraged citizens to remain calm . Complete coverage : Theater shooting in Aurora . Read more : Norway killer Anders Breivik ruled sane , given 21-year prison term .
Police began investigating man 5 months ago after Internet messages about Columbine . Police tracked his efforts to acquire explosive materials via the Internet . Suspect arrested Wednesday as he received the materials at his home , police say . In his personal diary , `` he showed a hatred for society , '' police say .