New York will put up checkpoints at key entry points to the city to ensure that travelers are complying with the state’s quarantine requirements, Mayor Bill de Blasio announced Wednesday.

Visitors from 35 US states, including Florida and Texas, are currently required to quarantine for two weeks after entering New York in an attempt to contain the spread of coronavirus. De Blasio said law enforcement agencies will operate “traveler registration checkpoints” at major bridge and tunnel crossings into the Big Apple from Thursday.

Travelers from the states on the quarantine list will have to fill out a health form that will help authorities with contact tracing in case of an infection.

Arrivals at New York’s airports already have to complete the form. Anyone who refuses to is subject to a $2,000 fine. “New York City is holding the line against COVID-19, and New Yorkers have shown tremendous discipline,” de Blasio said.

“We’re not going to let our hard work slip away and will continue to do everything we can to keep New Yorkers safe and healthy,” he added.

COVID-19 has killed more than 32,000 people in New York state, according to a running tally by Johns Hopkins University.

The city was the epicenter of America’s outbreak back in March and April but the spread of the virus has largely been brought under control, even as cases have surged elsewhere in the country. Individuals who violate New York’s quarantine can be fined $10,000.