OAK CREEK, Wis. — A rampage at a Sikh temple that left seven dead and three critically wounded Sunday was called a possible case of domestic terrorism, prompting the FBI to take over the investigation.

One of the dead was the suspected gunman. Tattoos on his body and certain biographical details led to the preliminary terrorism classification, according to a federal official, who spoke on condition of anonymity because he was not authorized to speak to the press.

In an afternoon press conference, Oak Creek Police Chief John Edwards called it a case of domestic terrorism. Later, the FBI agent in charge of the case urged caution. “While the FBI is investigating whether this matter might be an act of domestic terrorism, no motive has been determined at this time,” Teresa Carlson of the FBI’s Milwaukee division said in a statement Sunday night.

Officials had not released the gunman’s identity by Sunday night, but authorities surrounded a house where he was believed to have lived. The rented home was in Cudahay, another Milwaukee suburb, about six miles from the temple.

The horror began about 10:30 a.m. in suburban Oak Creek, just south of Milwaukee on Lake Michigan.

As worshipers assembled to eat, sing and pray, a gunman entered the temple and opened fire, police said. People scurried for hiding places, including several women who sought refuge in a pantry. One phoned a relative and warned her in whispers to stay away from the temple.

In text messages and hushed phone calls, parishioners told authorities there were multiple gunmen. Later, however, officials said they thought there had been just one, and he lay dead in the parking lot, slain in a firefight with police. Witnesses described him as white, with a large build and in his 30s.

Edwards said two officers had responded to the initial 911 call and one of them was “ambushed” while checking on a victim. With that officer shot several times, the gunman turned on the other officer, who returned fire and killed the shooter, Edwards said. The wounded officer was expected to survive.

“Because of the heroic actions of our officers, they stopped this from being worse than it could have been,” the police chief said.

Officials said it took a long time for SWAT teams to clear the temple because of the conflicting reports about multiple shooters.

Survivors were taken from the temple to a bowling alley across the street, where officials questioned them, Edwards said. He confirmed that authorities had recovered weapons but declined to say how many or what kind.

The violence left congregants desperate for answers, temple member Jagpal Singh said.

“Over and over, [we] keep asking ... ‘Did we do anything wrong?’ ” he said.

The designation of “domestic terrorism” under the FBI’s rubric — which was not applied to the Aurora, Colo., theater shooting that killed 12 and wounded 58 — implies a political agenda.

Sikhs are often mistaken for Muslims because of the religion’s requirement that men wear turbans and leave their beards uncut. There have been incidents since Sept. 11, 2001, in which Sikhs have been victims of hate crimes, said Jasjit Singh, executive director of the Sikh American Legal Defense and Education Fund. He cited vandalism at gas stations, beatings of taxi drivers and instances of school discrimination.

“Given that overview, when something like this happens, our first thought is that this isn’t an isolated incident,” Singh said. “It’s an outgrowth of a xenophobic trend toward our community members.”

The Sikh Temple of Wisconsin, founded in 1997, has a congregation of 350 to 400 members, according to the temple’s website.

Satwant Singh Kaleka, temple president, was among the shooting victims, according to his son, Amardeep Kaleka. He was told that his father was shot trying to tackle the gunman. The younger Kaleka also said a priest was shot in the hip or leg and was “bleeding profusely.”

Kaleka spoke with his mother, who was in another section of the temple. She told him that the gunfire came in individual pops and that she heard 40 or 50 gunshots, he said.

Jaspreet Singh, 16, of Oak Creek, said her mother was among those who hid in a pantry and, from there, called a relative with a warning.

“It’s really scary,” Singh said. The temple “is a place that’s so peaceful.”

Her mother safely made it out of the temple and to the bowling alley across the street, she said.

Harpreet Kapur, 22, a member of the temple, said the incident “felt as tragic for me as 9/11.”

“I felt the same thing I felt that day,” Kapur said, cradling his young son.

Both President Obama and presumptive Republican presidential candidate Mitt Romney issued statements condemning the violence. Obama said he was “deeply saddened” by the incident, and Romney called it a “senseless act.”

The shootings began about an hour before an 11:30 a.m. service, which temple member Harvinder Ahuja estimated is attended about 350 people each Sunday.

“It’s a good thing it happened” earlier, Ahuja said. “If it happened at 11:30, a lot more people would have been injured or died.”

dhinkel@tribune.com

rsobol@tribune.com

brian.bennett@latimes.com

Hinkel reported from Oak Creek, Sobol from Chicago and Bennett from Washington. John P. Huston and Erin Meyer in Chicago contributed to this report.