The Edwards

At least seven people were killed, including the suspected gunman, in a mass shooting at a Sikh temple in Oak Creek, Wis., south of Milwaukee on Sunday.

According to police, 911 dispatchers received multiple calls from the temple at approximately 10:25 a.m. local time. An officer who responded to the scene was treating a victim when he was "ambushed" by the suspected gunman in the parking lot, Oak Creek Police Chief John Edwards said. The veteran officer was shot multiple times and rushed to Milwaukee's Froedtert Hospital where he underwent surgery, Edwards said.

The suspect was shot and killed by a second officer, police said. The gunman was not identified, and no motive was released. But according to Thomas Ahern, spokesman for the ATF Chicago bureau, the gunman was a white male in his early 40s.

Sources told ABC News the suspect was a "white supremacist" or "skinhead." And officials told NBC News he had "some kind of radical or white supremacist views," but was apparently not a member of any kind of radical organization. His past run-ins with law enforcement were described as minor.

Tactical units conducting a sweep of the 17,000-square-foot temple discovered four bodies inside and three—including the gunman—in the parking lot. Edwards said "weapons" were recovered, but would not elaborate. According to CNN, two semi-automatic handguns were recovered at the scene, and member of the temple described the gunman as tall male with what appeared to be a "9/11 tattoo." Officials told NBC the suspect, who served in the U.S. Army, had many tattoos.

There were initial, unconfirmed reports of multiple shooters and a hostage situation, though police said they believe there was just one gunman.