The gunman yesterday was also injured and receiving medical care, according to the local NBC affiliate.
The meeting of town supervisors in Ross Township, in the eastern US state's Monroe County, was slated to begin at 7 pm local time (0430 IST). Just 23 minutes later, emergency calls started coming in, the broadcaster said.
Two of the injured were airlifted for treatment in the Lehigh Valley, while the other two were being treated locally.