Moscow authorities will enforce its citywide quarantine using QR codes assigned to residents as passes to leave their homes, the Meduza news website reported Sunday, citing a source close to the Russian capital’s coronavirus crisis center.

The partial lockdown in the city of 12.7 million came into force Monday, allowing Muscovites to leave their homes only to seek emergency medical care, shop for food or medicine, go to work, walk pets or take out the garbage. The mayor’s office will deploy “smart monitoring” to enforce the new rules and will develop a special pass system for residents to leave their houses, Mayor Sergei Sobyanin said. 

Authorities will issue QR code passes to people who register with their home address on the mayor’s website, Meduza cited its unnamed source as saying. Muscovites will be required to show these QR codes to police officers on demand.

Sobyanin’s announcement of the strict self-isolation rules allows movement around Moscow without special passes until the city administration issues a separate decree on what form these passes would take. 

Sobyanin did not specify the punishments for violating the indefinite quarantine. Meduza cited its source as saying that these would likely take the form of administrative fines.

Moscow authorities are also considering deploying police officers to patrol the streets during the quarantine, Meduza cited its source as saying.

An overwhelming majority of Russia’s coronavirus cases have been registered in Moscow, with more than 1,000 out of 1,534 cases and nine out of 11 deaths recorded in the capital.

At least one lawmaker and several lawyers told Russian media that only President Vladimir Putin and Russia’s senate have the constitutional authority to restrict freedom of movement via a state of emergency. The Kremlin, meanwhile, said it approved of Sobyanin’s strict measures to stave off the deadly pandemic.

“Gradually, but steadily, we will tighten the control necessary in this situation,” Sobyanin said.