OAK CREEK, Wisconsin (CNN) -- As a lone male voice sang hymns over somber music, mourners at a memorial service Friday filed slowly past the coffins and photos of six Sikh worshippers shot to death at their Wisconsin temple.

The killings Sunday at a suburban Milwaukee gurdwara, or Sikh house of worship, ended when gunman Wade Michael Page shot himself after being wounded by police fire.

U.S. Attorney General Eric Holder was scheduled to speak later Friday at the memorial service in the gymnasium at Oak Creek High School.

As the service began, three Sikh musicians in dark turbans sat cross-legged on the ground next to a row of six coffins and large, framed photos of the dead.

Hundreds of people slowly walked past, including Sikhs in their traditional turbans and non-Sikhs using scarves and handkerchiefs to cover their heads in keeping with Sikh custom.

"You have taken this life. This is your will," a prayer leader said between hymns. "We accept your will. Please give us strength to bear this loss."

Overhead, a large video screen displayed projected photos of the dead and wounded in the attack, including police Lt. Brian Murphy, who remains hospitalized from multiple gunshot wounds after being the first responder to the temple on Sunday.

Killed were five men -- Satwant Singh Kaleka, 65; Sita Singh, 41; Ranjit Singh, 49; Prakash Singh, 39; Suveg Singh, 84 -- and one woman, 41-year-old Paramjit Kaur.

Two other Sikhs wounded in the attack also remain hospitalized, while another was treated and released earlier this week.

On Thursday, temple members swept, scrubbed and painted over damage to their building after investigators allowed them back inside. A lone bullet hole remained in a metal door frame, which members say won't be repaired.

The attacker was a 40-year-old former soldier-turned-front man for a white supremacist rock band. He killed himself in the parking lot of the gurdwara after being shot by a police officer, the FBI said Wednesday.

Investigators say they found no clues to explain why Page went on the killing spree. Former Army colleagues said he espoused racist views during his military stint in the 1990s that became more pervasive after he left the service.

The incident occurred slightly more than two weeks after a shooting at a movie theater in Aurora, Colorado, left 12 people dead and 58 wounded.

Civil rights leader Jesse Jackson, who visited the gurdwara on Thursday, said more massacres will come unless the United States tightens up its gun laws.

"It's easy to be polite to say 'We're so sorry this happened' and give the same speech at the next killing a month from now," Jackson said, calling for a move from "politeness to a change in policy."

A CNN/ORC International poll released Thursday indicates that the public remains divided on gun laws, with 50% saying they favor no restrictions or only minor restrictions on firearm ownership and 48% supporting major restrictions or a complete ban by individuals except police and other authorized personnel.

Those numbers are identical to where they were in 2011, and the number who support major restrictions or a complete ban has remained in the 48%-to-50% range for more than a decade.

The CNN survey was conducted by ORC International on Tuesday and Wednesday, after the attack on the Sikh temple.

CNN's Tom Cohen, Poppy Harlow and David Mattingly contributed to this report.