An earthquake has shaken an area in northern Iran, injuring three people and causing damage in three villages. The official IRNA news agency quoted a local governor as saying no-one was killed in the quake, which the seismological centre said had a magnitude of 5.9 and occurred in Semnan province.The US Geological Survey said the quake was centred about 150 kilometres south of the city of Gorgan, north-east of the capital Tehran, at a depth of 10 kilometres.