Five Tunisian political parties have decried what they said was violence against their supporters at a demonstration in opposition to an upcoming referendum. Kais Saied, the country’s president, is aiming to put a new constitution to a vote on 25 July, before holding elections in December. Demonstrations were held on both sides of the debate in Sousse city on Saturday, with fighting breaking out. Tunisian authorities then stepped in, Anadolu Agency reported on Monday. Five parties who earlier this month formed a campaign to scrap the July constitutional referendum alleged Saied loyalists had a…