Nine of the 13 fires were reported Sunday, all within a one-mile radius.
The first started around noon on the 500 block of Division Street. Firefighters arrived to find heavy conditions showing at a vacant home, officials say.
The second call came in around 2:30 p.m. for a fire near the intersection of 8th and Cherry, also at a vacant home. While crews were responding, a third fire was reported, less than 20 minutes later, at another vacant home on the 500 block of Division Street.
Shortly around 5 p.m., firefighters responded to a fire at a vacant home on the 1300 block of Park Boulevard. Less than 15 minutes later, another fire was reported, again at a vacant home on the 1000 block of Princess Avenue.
Fire No. 6 left two firefighters suffering from minor injuries after responding to a fire at a vacant home on the 500 block of Lansdowne Avenue.
But the calls didn't stop there.
A fire at a vacant home on the 1200 block of Sycamore Street went to two alarms. It wasn't long before fire No. 8 started at 8th and Pine streets.
In a twist of events, two vans were set on fire in a back ally of Royden Street and Broadway.
Fire officials from Pennsauken and surrounding areas sent trucks to Camden to assist firefighters.
The injured firefighters were treated for injuries ranging from exhaustion to a hand injury, officials say.
No civilian injuries were reported.
Officials said an arson task force has been formed, but stopped short of calling the fires an act of arson.
The cause of the fires is unknown at this time, and investigators are asking for your help.
"We don't know how these fires are being started at this point, but look for suspicious activity, people avoiding eye contact, walking through alleys," said Camden County Police Capt. Greg Carlin. "We think most times they're entering from the rear of a vacant property."
Anyone with information is asked to call 856-757-7042.