OAK CREEK, Wis. — The priests had gathered in the lobby of the sprawling Sikh temple here in suburban Milwaukee, and lunch was being prepared as congregants were arriving for Sunday services.
Instead of worshippers, though, an armed man stepped through the door and started firing.
In an attack that the police said they were treating as ‘‘a domestic terrorist-type incident,’’ the gunman stalked through the temple around 10:30 a.m. Congregants ran for shelter and barricaded themselves in bathrooms and prayer halls, where they made desperate phone calls and sent anguished texts pleading for help as confusion and fear took hold. Witnesses described a scene of chaos and carnage.
Jatinder Mangat, 40, who was on his way to the temple when he heard reports about the shooting, said he had tried to call his uncle, the temple’s president, but instead reached the head priest, Gurmail Singh.
‘‘He was crying. Everyone was screaming,’’ Mangat said. ‘‘He said that my uncle was shot and was lying on the floor and asked why you guys are not sending an ambulance and police.’’
Singh, he said, had locked himself in a bathroom with four other people, including two children.
Six people were killed and three others were wounded on Sunday at the 17,000-square-foot Sikh Temple of Wisconsin in Oak Creek, a city of about 35,000 just south of Milwaukee, officials said.
The gunman’s rampage ended when one of the first police officers to arrive shot and killed him. Another police officer, who tried to aid a victim, was ambushed by the gunman and shot multiple times. He was in critical condition but was expected to survive, the authorities said.
The police did not release any details about the gunman or a possible motive for the shooting, beyond raising the prospect of terrorism. Thomas Ahern, a spokesman for the Bureau of Alcohol, Tobacco, Firearms, and Explosives, said the killer was a 40-year-old white man.
John Edwards, the police chief in Oak Creek, said at a news conference that weapons had been found at the scene. He said the FBI would lead the investigation.
‘‘This remains an active investigation in its early stages,’’ Teresa Carlson, the special agent in charge of the FBI’s Milwaukee division, said in a statement. ‘‘While the FBI is investigating whether this matter might be an act of domestic terrorism, no motive has been determined at this time.’’
The shootings reverberated from this small community to Washington and beyond, including India, where the religion was founded and many of the congregants have family ties.
President Obama and his Republican challenger, Mitt Romney, released statements on Sunday expressing sorrow.
‘‘Michelle and I were deeply saddened to learn of the shooting that tragically took so many lives in Wisconsin,’’ the president said. ‘‘At this difficult time, the people of Oak Creek must know that the American people have them in our thoughts and prayers, and our hearts go out to the families and friends of those who were killed and wounded.’’
Romney called the shootings ‘‘a senseless act of violence and a tragedy’’ that he said should never befall any house of worship.
‘‘Our hearts are with the victims, their families and the entire Oak Creek Sikh community,’’ Romney said. ‘‘We join Americans everywhere in mourning those who lost their lives and in prayer for healing in the difficult days ahead.’’
Many members of the close-knit Sikh community here said the attack had shattered their sense of security.
‘‘Everyone here is thinking this is a hate crime for sure,’’ said Manjit Singh, who goes to a different temple in the region. ‘‘People think we are Muslims.’’
Though violence against Sikhs in Wisconsin was unheard-of before the shooting, many in this community said they had sensed a rise in antipathy since the attacks on Sept. 11 and suspected it was because people mistake them for Muslims.
Followers of Sikhism, or Gurmat, a monotheistic faith founded in the 15th century in South Asia, typically do not cut their hair, and men often wear colorful turbans and refrain from cutting their beards.
‘‘Most people are so ignorant they don’t know the difference between religions,’’ said Ravi Chawla, 65, a businesswoman who moved to the region from Pakistan in the 1970s. ‘‘Just because they see the turban they think you’re Taliban.’’
There are around 314,000 Sikhs in the United States, according to the Association of Religion Data Archives. The temple in Oak Creek, one of two large congregations in the Milwaukee area, was founded in 1997 and has about 400 worshippers.
At a news conference, Edwards described a dramatic scene when officers arrived soon after the first 911 call. After the gunman ambushed the first officer, Edwards said, another police officer exchanged fire with the gunman, bringing him down.
Bradley Wentlandt, the chief of police in nearby Greenfield, said that the wounded officer was a 20-year veteran whose actions probably saved many lives.
Four bodies were found inside the temple and three outside, including that of the gunman, Wentlandt said.
Three men with gunshot wounds were admitted to Froedtert Hospital, the Milwaukee region’s main trauma center, said Nalissa Wienke, a spokeswoman for the hospital. One victim had been shot in the head and extremities and another in the abdomen. The third was described as having neck wounds.
Outside the temple here, friends and relatives were struggling to understand what had happened. Many in the community had contacted friends and family who were in the temple when the violence broke out.
Harpreet Singh, a nephew of the temple president, said his aunt, the president’s wife, was in the kitchen with other women preparing food for services when they heard gunshots.
“She said they heard a bang, bang, bang,’’ Singh, 36, said in a telephone interview from the basement of a bowling alley near the temple, where the police and FBI agents were interviewing survivors.
Singh, recounting the shooting as told to him by his aunt, Satpal Kaleka, said the women had hidden in a nearby pantry.
The women escaped, witnessing the gunman’s carnage along the way, Singh said.
Singh was on his way to services with his wife, two children and his parents when the police stopped them outside the parking lot.
‘‘There were police cars running into the complex,’’ he said. ‘‘A couple of weeks ago some kid had set off a fire alarm, so we thought something like that had happened.’’