A "powerful explosion" has occurred in Sweden's capital Stockholm, local media is reporting. Police have deployed several patrols to the area and a street has been blocked off, however authorities have said it is unclear what has taken place. Emergency services are also on the scene. The blast took place in the area around Brännkyrkagatan on Södermalm at 11:40am local time. "We are there to investigate what happened , but at present it is unclear what happened," said Albin Näverberg, spokesperson for the police in Stockholm, told Aftonbladet. There are currently no plans to evacuate the area, he said. According to Sputniknews, windows of several apartments have been smashed by the blast. It's unclear whether anyone has been injured as yet.