OAK CREEK, Wis. - A shooting during Sunday services at a Sikh temple left at least seven people dead, including a gunman, and at least three critically wounded, and police said they were still searching for other assailants.

A woman prays near a Sikh temple in Oak Creek, Wisconsin August 5, 2012 following a mass shooting inside and outside the temple. A shooting during Sunday services at a Sikh temple left at least seven people dead, including a gunman, and at least three critically wounded, police and hospital officials said. [Photo/Agencies]

The mass killing began when a white gunman or gunmen walked into the kitchen of the Sikh Temple of Wisconsin about 10:30 CDT (1530 GMT) and started shooting, according to congregation members in touch with people inside the building.

"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 at the temple in a suburb south of Milwaukee.

Greenfield Police Chief Bradley Wentlandt, speaking for all law enforcement at the temple, told reporters four people were killed inside the temple. Three were shot dead outside, including a gunman killed by a police officer.

He declined to say whether there was more than one shooter, but hours after the attack heavily armed officers were still searching the sprawling temple complex for other suspects.

Milwaukee's Froedtert Hospital said three men had been brought in wounded and were in critical condition. One was in the operating room, the hospital said in a statement.

The 20-year veteran officer who exchanged fire with the gunman was hit several times, Wentlandt said. He was taken to a hospital and is expected to survive.

Witnesses said hostages were being held inside the temple but police did not confirm this.

President Barack Obama, alerted of the shooting at the Camp David presidential retreat in Maryland, said he was "deeply saddened" by the attack, according to a White House statement. He said his administration would give whatever aid was needed to respond to and investigate it.

The Indian embassy in Washington said it was in touch with the White House's National Security Council about the shooting and an Indian diplomat had been sent to the Sikh temple in Wisconsin.

The mass killing in Oak Creek is yet another in a recent rampage by gunmen in suburban America.

In July, 12 people were killed and 58 wounded when a shooter opened fire at a screening of the latest Batman movie in the Denver suburb of Aurora, Colorado. In January 2011, then-congresswomen Gabrielle Giffords was the target of an assassination attempt in which six people were killed and 13 were wounded.