Eighteen people were injured and 42 detained in Berne Saturday when police clashed with left-wing demonstrators protesting at a rally of the nationalist Swiss People's Party (SVP), according to DPA. The party had called on thousands of its supporters to take part in a pre-election rally at the main square before the capital's parliament building. Demonstrators disrupted the event, prompting the rally organisers to seek police protection. Police then moved in using teargas. The violence spilled over and nearby streets saw shops and cars damaged. The SVP - which has campaign posters showing white sheep kicking a black sheep off a Swiss flag - has been recently criticised for its hard-line views on immigration. The party has also campaigned against minarets in Swiss cities. The clashes came two weeks before 21 October parliamentary elections which recent polls have forecast the SVP winning most votes.