Greece on Friday said it would require travellers crossing its land border with Bulgaria to provide proof they have tested negative for coronavirus as cases surged elsewhere in the Balkans. Greece's sole border crossing currently open to tourists is with Bulgaria, and is crossed by thousands of mainly Balkan travellers every day. "All those entering for non-essential reasons from July 14... are obliged to show a negative (nasal swab) test result up to 72 hours prior to entry," government spokesman Stelios Petsas told reporters. The move came after Bulgaria registered a daily record of 240 new infections on Thursday. Romania on Thursday also reported its biggest daily increase since the pandemic started at 614 cases. In Serbia, where there are have been violent protests against the government's handling of the pandemic, infections have also increased in the past few weeks. Greek authorities are already handling several confirmed virus cases in holiday areas after reopening regional airports to international flights on July 1. In the spa town of Edipsos on the island of Evia, nearly 90 Serbian tourists were tested this week after a pair vacationing in the area were found to be infected. "Relaxing (lockdown) measures has caused a rebound in the first wave," Athanassios Tsakris, head of the department of microbiology at the University of Athens medical school told Skai TV. "It's possible that we will see a further increase (in cases)," he said. jph/erc