Update 1:24 PM ET:
From the Journal-Sentinel:
Two shooters are possibly still inside with children as hostages, according to someone who sent a text message to a Journal Sentinel reporter.
Update 1:31 PM ET:
Pictures from Chopper 4 showed at least four people who were killed.
One witness told Newsradio 620 WTMJ's Dan O'Donnell that at least two, possible four gunman were hiding inside the temple.
Oak Creek Police did not initially confirm those reports, and they did not confirm that they have a shooter in custody.
Authorities have set up a staging area near the temple and closed off roads in the area.
Update 1:55 PM ET:
From USA Today:
A SWAT team went into the building an brought out an undetermined number of injured people, the paper reports. AP says there are more than a dozen ambulances parked outside the temple, and that police have corralled media and a handful of bystanders to an area near the temple.
Update 2:02 PM ET:
MSNBC reports that a police officer who responded to the scene exchanged fire with a suspect, was shot, and is expected to recover. Watch their live coverage here.
Update 2:46 PM ET:
The AP reports that three victims are being treated at a nearby hospital:
Three shooting victims, all men, were taken to Froederdt Hospital in Milwaukee, the main trauma center for the area, spokeswoman Carolyn Bellin said. One was in the operating room, another in a surgical intensive care unit and the third was being evaluated in the emergency room, she said.
Update 2:48 PM ET:
Police Chief Brad Wentlandt announced on CNN that four are dead in the temple, three dead outside the temple, one of whom is the shooter.
Law enforcement is not sure if there is more than one shooter. "We have not identified additional shooters in the temple or on the scene. At this point we're not sure if there was an additional shooter," Wentlandt said. "That will be part of this ongoing process."
The gunman was reported to be fatally shot by a police officer.
A police briefing on the situation is expected at 3:30 PM local time.
Update 4:30 PM ET:
The police briefing has been pushed to 4:00 PM local time.
Via CNN, Wisconsin Gov. Scott Walker released the following statement:
"While the situation in Oak Creek continues to develop rapidly, we are working with the FBI and local law enforcement. I became aware of the situation late this morning and continue to receive updated briefings.
Our hearts go out to the victims and their families, as we all struggle to comprehend the evil that begets this terrible violence.
At the same time, we are filled with gratitude for our first responders, who show bravery and selflessness as they put aside their own safety to protect our neighbors and friends.
Tonette and I ask everyone to join us in praying for the victims and their families, praying for the safety of our law enforcement and first responder professionals and praying for strength and healing for this entire community and our state."
Update 4:48 PM ET:
From the White House pool report:
The President was notified of the Wisconsin shooting shortly before 1 p.m. by his Homeland Security Advisor, John Brennan. The President continues to receive updates on the incident, the official said.
Update 5:19 PM ET:
In a briefing on the shooting that took place at a Sikh temple in Oak Creek, Wisocnsin on Sunday morning, Police Chief John Edwards said that the event is being treated as a "domestic terrorist-type incident" and that the FBI is therefore involved.
The department will hold a second briefing at 10 AM CT Monday.
Edwards said there were a total of seven people dead and three injured, including a police officer.
Update 5:25 PM ET:
The Embassy of India in Washington, D.C. is monitoring the situation and released the following statement:
We have seen reports on the tragic incident earlier today of firing at a group of worshippers in a Gurudwara in the Milwaukee suburb of Oak Creek, Wisconsin. The Embassy is seized of the situation and has been in touch with the National Security Council in Washington, D.C. Our Consulate General in Chicago too has been in close touch with the local authorities to monitor the situation. An official has been deputed to visit the site to ascertain the situation on-the-spot.
A majority of Sikhs live in India.
Sahil Kapur contributed to this story.