Swedish police arrested four people on suspicion of preparing a terror attack and evacuated an arts centre in Swedens second largest city on the eve of the 9/11 anniversary, officials said on Sunday. The four were arrested in the west coast city of Goteborg and were suspected of plotting terrorism, said Sara Kvarnstrom, spokeswoman for the Swedish security police, SAPO. She declined to give details on the arrests and wouldnt say whether they were linked to the 10-year anniversary of the Sept. 11 terrorist attacks in the United States. Ms. Kvarnstrom said SAPO saw no reason to raise its terror alert level, which has been at elevated since October. Our assessment is that there is no reason for public concern at the moment, she told The Associated Press.