<p><br /> Two explosions in central Stockholm have killed one person and injured two, causing panic among Christmas shoppers.<br /> </p><p><br /> A car exploded near Drottninggatan, a busy shopping street in the centre of the city.<br /> </p><p><br /> Shortly afterward, a second explosion was heard higher up on the same street, and a man was found injured on the ground. He was later pronounced dead.<br /> </p><p><br /> Two other people were taken to the hospital, but it was not immediately clear in which explosion they were hurt.<br /> </p><p><br /> Rescue services spokesman Roger Sverndal said the car that exploded contained gas canisters.<br /> </p><p><br /> Sjolander said it was unclear what caused the second explosion and if the two blasts were linked, but said a police bomb squad has been sent to the site.<br /> </p><p><br /> Sweden - which has so far been spared of any large attacks - raised its security threat alert level from low to elevated in October because of "a shift in activities" among Swedish-based groups that could be plotting attacks there.<br /> </p><p><br /> The security police said that the extremist threat remained low compared to that in other European countries, and no attack was imminent.<br /> </p>
