People wearing face masks walk in the Old Town of Warsaw, Poland, June 14, 2020. Poland reopened its borders with European Union (EU) countries at midnight on Friday, ending a travel lockdown that was in place since March 15 due to the COVID-19 pandemic. (Xinhua/Zhou Nan)

People wearing face masks walk in the Old Town of Warsaw, Poland, June 14, 2020. Poland reopened its borders with European Union (EU) countries at midnight on Friday, ending a travel lockdown that was in place since March 15 due to the COVID-19 pandemic. (Xinhua/Zhou Nan)

Customers visit a restaurant in the Old Town of Warsaw, Poland, June 14, 2020. Poland reopened its borders with European Union (EU) countries at midnight on Friday, ending a travel lockdown that was in place since March 15 due to the COVID-19 pandemic. (Xinhua/Zhou Nan)

A girl enjoys herself on a brick wall in the Old Town of Warsaw, Poland, June 14, 2020. Poland reopened its borders with European Union (EU) countries at midnight on Friday, ending a travel lockdown that was in place since March 15 due to the COVID-19 pandemic. (Xinhua/Zhou Nan)

People sit on a brick wall in the Old Town of Warsaw, Poland, June 14, 2020. Poland reopened its borders with European Union (EU) countries at midnight on Friday, ending a travel lockdown that was in place since March 15 due to the COVID-19 pandemic. (Xinhua/Zhou Nan)