Authorities in Peru have opened an investigation into violent clashes that broke out between police and protesters on the third day of demonstrations over a local university.<br /><br /> The clashes in the country’s southwest left some 20 people, mostly police officers, injured. <br /><br /> Images from the scene showed one officer being struck on his helmet with a large rock. <br /><br /> Other footage showed an injured protester being carried away by other demonstrators.<br /><br /> Local people are angry that the Autonomous University of Tayacaja, which was built five years ago, has still not been opened.<br /><br /> Four injured police officers were reportedly held by the protesters for some 20 hours before being released.<br /><br /> Police were pelted with rocks, while officers fired back with tear gas.<br /><br /> The clashes broke out when police attempted to clear protesters off a road.<br /><br /> Peru’s Interior Minister, Jose Perez Guadalupe, said: “I have always said, and I reiterate: protesting is one thing, violence is another. <br /><br /> “And the police kn
