A mother and five children were found dead in their home late Thursday, police said.

"There is a lot of trauma," said Sioux City Police Chief Joe Frisbie. "It is evident that this is not a suicide.

"It appears that all six persons have been murdered," Frisbie said. "There is no question we have a homicide here, probably the worst we have seen in this community ever."

Prior to Thursday, the chief said the worst case he had seen was a triple murder in the Morningside area about 25 years ago.

Frisbie said the children ranged in age from 5 to 12.

The bodies were found by a baby sitter shortly before 6 p.m. in their home at 311 West St., a low-income westside neighborhood. Authorities would not say how they died, but apparently the bodies had been in the home for a few days.

Police said they received a call of two children found on the second floor of the home. When officers arrived, they found the bodies of five children and their mother.

Frisbie was unable to confirm the names of the six victims Thursday night as police hadn't obtained a search warrant until after 9 p.m. The scene drew onlookers as police waited outside the home and waited for the warrant.

Police also reported that a man's body was found at another residence in the county club area about the same time, also being investigated as a homicide.

A police spokesman said the man's body was found in the entryway of a house. He was found by a co-worker because he had not shown up for work.

The body had not been identified, but Frisbie said there was no doubt it was a "very heinous homicide. There's no doubt there's a lot of trauma." He declined to speculate on how the trauma occurred.

"We can't really get a good view of this person," Frisbie said. "There are reasons we can't see this person in such a way we'd be able to identify him. It may mean something to the perpetrator," Frisbie said. "Until our identification people and coroners get involved we won't know for sure." He said technicians would make the first contact with the body.

Frisbie said that when "the person who lives here" hadn't been to work "in awhile," an employee went to the house to check on him, discovered the body and called police.

They said the two cases were apparently not related, although the man had also been dead for some time.

The Iowa Department of Criminal Investigation was called in to assist with the investigation of the deaths of the woman and children.

Police said they had no immediate suspect in either case.