At least four people are dead and dozens injured after a small private plane hit Italy's tallest skyscraper, causing a massive explosion that shook windows of nearby blocks and carved a huge gash into the side of the 32-storey structure. Interior Minister Claudio Scajola said the crash appeared to be an accident and an Italian law enforcement official told CNN they had no evidence of any link to terrorism. In Washington, sources said there was no intelligence about a specific terrorist attack targetting Italy. Thirty to 40 people from the 127-metre-high (415-feet) tower in the centre of the city were taken to hospital with injuries, mostly broken arms and legs, a reporter on the scene told CNN. One Milan hospital, Fatebene Fratelli, said it had received 20 injured, including a woman with burns. A number of witnesses said they saw flames coming from the plane before it hit, according to Italian radio.