And Serbia's president warns residents that Belgrade's graveyards won't be big enough to bury the dead if people ignore his government's lockdown orders.

Since President Aleksandar Vucic announced an open-ended state of emergency on March 15, parliament has been sidelined, borders shut, a 12-hour police-enforced curfew imposed and people over 65 banned from leaving their homes — some of Europe's strictest measures to combat the COVID-19 pandemic.

The Serbian leader, who makes dramatic daily appearances issuing new decrees, has assumed full power, prompting an outcry from opponents who say he has seized control of the state in an unconstitutional manner.

Rodoljub Sabic, a former state commissioner for personal data protection, says by proclaiming a state of emergency, Vucic has assumed "full supremacy" over decision-making during the crisis, although his constitutional role is only ceremonial.

"He issues orders which are automatically accepted by the government," Sabic said. "No checks and balances."