Salt Lake City ? A man with a shotgun entered a shopping mall and began randomly shooting customers Monday night, killing five people and injuring at least four others before being killed, police said.

More than three hours later, police still were searching stores for shocked shoppers and employees who were hunkered down awaiting a safe escort from the Trolley Square mall.

At least four people were hospitalized, three in critical condition and one in serious condition, hospital spokesmen said.

Two of the critically injured were a 16-year-old man and a 50-year-old man, a spokesman said.

Authorities offered few details about the shootings but said the gunman entered the enclosed mall about 7:45 p.m. CST.

The two-story building, southeast of downtown, is a refurbished trolley barn, with a series of winding hallways and about 80 stores.