A man sits on a rock as police investigate the Sikh Temple of Wisconsin in Oak Creek, Wis., after a shooting Sunday, Aug 5, 2012. A gunman killed six people at the suburban Milwaukee temple in a rampage that left terrified congregants hiding in closets and others texting friends outside for help. The suspect was killed outside the temple in a shootout with police officers.

The Associated Press

Published Sunday, Aug. 05 2012, 1:07 PM EDT

Police in Wisconsin say seven people are dead at a Sikh temple near Milwaukee, including the suspected gunman.

The FBI says it is investigating whether the shootings were an act of domestic terrorism. FBI Special Agent in Charge Teresa Carlson says in a Sunday night statement that no motive has been determined for the attack at the Sikh Temple of Wisconsin. She says the investigation is in its early stages.

He says one of those killed outside is the suspect. Oak Creek Police Chief John Edwards says the suspect “ambushed” one of the first officers to arrive at the scene as the officer tended to a shooting victim.

Mr. Edwards says the suspect shot the officer multiple times outside the Sikh Temple of Wisconsin on Sunday morning. A second officer then exchanged gunfire with the suspect and fatally shot him. Mr. Edwards says the officer who was ambushed is undergoing surgery at a nearby hospital and is expected to survive.

Police do not believe a second shooter was involved, contradicting earlier reports of multiple shooters.

At least three men have been admitted to a Milwaukee-area hospital, including one police officer. A Froederdt Hospital spokeswoman says one of the men is in the operating room, another is in a surgical intensive care unit and the third is being evaluated in the emergency room. All three are considered to be in critical condition.

The first official word from police was that they didn’t know how many victims or suspects were involved. But a short time later, after an extensive search of the temple, authorities said they did not believe there was more than one shooter.

“It was a very coordinated thing. It wasn’t haphazard,” temple member Amardeep Kaleka told CNN. He said his father was wounded in the attack.

“This is nerve-racking. No one really knows what’s going on. Nothing like this has ever happened before,” Mangat said. Later, when he learned of the deaths, he said, “It was like the heart just sat down. This shouldn’t happen anywhere.”

It is still unknown how many were wounded in the shooting. At least three priests may be among those shot, according to the Milwaukee Journal Sentinel.

According to the Journal Sentinel, one of the temple’s committee members said the motive for the shooting is unknown, but identified one shooter as a white male who is not a member of the temple, and suggested it may have been “a hate crime.”

U.S. President Barack Obama said Sunday that he and First Lady Michelle Obama had been “deeply saddened” to learn of a shooting that left at least seven people dead at a Sikh temple in Wisconsin.

“As we mourn this loss which took place at a house of worship, we are reminded how much our country has been enriched by Sikhs, who are a part of our broader American family,” he said, in a White House statement.

Police and ambulances have cordoned off the area, and tactical units are on scene, while officers were dispatched to another nearby temple as a precaution.

With reports from James Bradshaw and Reuters