Those Hummers are the vehicles of the National Guard, sent to protect so-called sensitive areas in the city, such as City Hall.
Members of the National Guard were deployed to Philadelphia as looting was occurring across the city late Sunday night and early Monday morning.
Looters swarmed a shopping center at Fox and Roberts in the East Falls section of Philadelphia just minutes after police left. When officers returned, the crowd scattered.
They left the Snipes USA athletic store nearly empty. One employee said looters even took the store's mannequins.
A store owner whose North Philadelphia business was targeted said the looters have been using social media to figure out where to strike.
"When one group comes from another area, they are using social media to overwhelm another area that's not being hit," said Paul Lim.
Sunday was the second day of looting which was seperate from the peaceful demonstrations to protest the death of George Floyd.
City leaders say the looters overwhelmed police, at times out numbering them 10 to one.
"Our officers did their best to maintain control last night, but they were out numbered pretty severely in most areas," said Philadelphia City Manager Brian Abernathy.
The National Guard stands watch over City Hall hoping to keep vandals and looters from making it their next target.
As the National Guard protects buildings, Philadelphia Police have more officers available to respond to the looting.
Between about noon on Sunday and midnight Monday morning, police said 138 people had been arrested.
"It's just a shame it had to come to this," said Lim.