Participants open the EXIT festival in Novi Sad, Serbia on July 4, 2019. Under the slogan "We are all one EXIT tribe," more than a thousand musicians have gathered here for Serbia's biggest music festival EXIT at the Petrovaradin Fortress. Organizers said they expected around 60,000 foreign tourists to attend this year's EXIT. Most of the hotels and rooms in Novi Sad have already been booked. The festival will last till July 7. (Xinhua/Nemanja Cabric)