The tragic killing of three police officers in Baton Rouge, Louisiana has led officials in Cleveland, Ohio to review their security plans in advance of this week’s Republican National Convention.

Cleveland’s plan includes more than 6,000 law enforcement officers who are tasked in part with securing a perimeter that covers 1.7 square miles. That’s nearly all of the city’s downtown.

It would be a tough task for the city’s 500 police officers to handle alone. So an additional 2,500 law enforcement officers from local departments around the country have come to Cleveland to provide assistance. There are also 3,000 federal law enforcement officials in Cleveland for the convention.

Some of the officers are patrolling on bicycles, which have proven to be an effective crowd control tool in other cities. Hundreds of officers on bicycles have been deployed in Cleveland. They can be used as a cavalry that can dismount use their bike to create a temporary blockade.

The Republican National Convention is expected to attract more than 50,000 people to Cleveland this week.