BRUSSELS (AP) — New coronavirus clusters have appeared as nations struggle to balance reopening economies with preventing a second wave of infections and deaths. In Europe, a debate has erupted over the summer travel season. Authorities in the Chinese city of Wuhan are moving ahead with efforts to test all 11 million residents for the virus after a handful of new infections were found. Lebanon reinstated a nationwide lockdown for four days after a spike in reported infections. European nations, meanwhile, have been seeking ways to potentially restart cross-border travel. The summer holiday season looms for countries whose economies rely on tourists flocking to beaches, museums and historical sites.