Hundreds of people packed a sweltering Emanuel African Methodist Episcopal Church inCharleston for an emotional memorial service on Sunday just days after a gunman, identified by authorities as a 21-year-old white man, shot dead nine black church members.

"We are reminded this morning about the freshness of death that comes like a thief in the night," the Reverend Norvel Goff told a mostly black congregation that swelled to about 400 people for a service remembering those killed on Wednesday in the latest US mass shooting.

Armed police searched bags at the door of the church, home to the oldest African-American congregation in the southern United States, and officers stood at intervals inside the church along the side of the nave and in the gallery.

Outside the church, a large, mostly white crowd gathered to express solidarity with those inside.

Goff's rollicking sermon brought people alternately to tears and laughter as the church reopened to worshippers for the first time since the shooting. They whooped, cheered and raised their hands, and ended the service with embraces after Goff, whose voice rose to a shout at times, encouraged them to "hug three people next to you and tell them, 'It's going to be alright.'"

The suspect, Dylann Roof, was arrested on June 11 and has been charged with nine counts of murder. Authorities say he spent an hour in an evening Bible study group at the church, nicknamed "Mother Emanuel" for its key role in US black history, before opening fire.

Federal investigators were examining a racist manifesto on a website that appeared to have been written by Roof. The site featured white supremacist writings and photos, apparently of Roof.

Goff was standing in for Clementa Pinckney, 41, senior pastor at Emanuel and a Democratic member of the state Senate who was killed in the massacre.

Among those at the service, which lasted more than two hours, were South Carolina Governor Nikki Haley, U.S. Senator Tim Scott, CharlestonMayor Joseph Riley and Republican presidential candidate Rick Santorum.

Riley called for stricter gun control laws on CNN.

"It is insane the number of guns and the ease of getting guns in America," Riley said. "It's not that people should not carry guns and all of that, it's just that there are so many of them and the ease of them and there is no accountability."

President Barack Obama on June 19 expressed frustration over the issue. He blamed the powerful National Rifle Association gun-rights lobby group and public apathy for the failure to implement new gun control measures.