Police officers are posted at street corners in downtown Philadelphia as protesters prepare for a sweltering day of marches and rallies ahead of the Democratic National Convention.

Several Sunday demonstrations are planned, including an anti-fracking march from City Hall to Independence Mall, near the Liberty Bell. Bernie Sanders supporters expect about 3,000 protesters will join them in a march from City Hall to a park near the convention site.

Temperatures are expected to reach the upper 90s; crowds can take advantage of “misting tents” and free water, compliments of the city.

The first march Sunday had the perennial problem in Philadelphia: parking. DC to DNC organizer Ed Higgins says organizing the crowd also delayed the march.

The four-day convention for Democrats to nominate Hillary Clinton for president begins Monday.

(AP)