One person has been killed and two others injured in two explosions that rocked the centre of the Swedish capital, Stockholm. A car blew up near the busy shopping street of Drottninggatan and another blast followed nearby minutes later. Swedish press attributed the second blast to a suicide bomber but police said no cause had yet been determined. A local news agency, TT, said it had received a threatening e-mail shortly before the blasts, which called for “mujahideen”, or Islamist fighters, to rise up in Sweden and Europe. Attacking the country over caricatures of the Prophet Mohammed drawn by Swedish artist Lars Vilks as well as Sweden's military presence in Afghanistan, the e-mail promised Swedes would “die like our brothers and sisters”. Sweden has 500 soldiers deployed in Afghanistan as part of the international peacekeeping force.