Maricopa County sheriff's deputies raided what they believed was an illegal immigrant drop house in north Mesa on Wednesday, arresting 13 people who were possibly also being held there against their wills.

Authorities did not know whether any of those arrested were kidnappers or "coyotes" - human smugglers - but were planning to question each one to find out.

The house, near Mesa Drive and McKellips Road, had two bedrooms and just one bathroom for the 12 men and one woman living there.

Some of the immigrants were bruised and slightly dehydrated when deputies arrived, but none appeared to have received the brutal treatment that sometimes occurs at drop houses, said deputy Doug Matteson, sheriff's spokesman.

"They might have some minor, minor bruising, but nothing that would require anyone to be taken to the hospital," he said.

Investigators first learned about the house, in the 300 block of East Kenwood Circle, through an anonymous tip to an illegal immigration hotline set up by the sheriff's office, Matteson said.

When investigators first arrived about 1:30 p.m., a man came outside and said he was being held against his will, Matteson said.

Before long, the sheriff's SWAT team - its members in black masks and flak jackets and bearing large guns - swarmed the small, white house and arrested everyone inside, handcuffing them and loading them into waiting vans and squad cars.

Shortly after the raid, deputies had not found any guns or other weapons inside the house, but they were still looking, Matteson said.

After the raid, a large white van with Arizona license plates could be seen parked in the backyard. A phone number was painted on the side, but that number had been disconnected as of late Wednesday.

Enrique Flores, who lives across the street from the house, said the whole operation appeared to be overkill.

"I think they're exaggerating," said Flores, 34. "I've seen the people. They don't appear to be bad people."

The house was a rental, and the people lived there about eight months, he said.

They were all between the ages of 25 and 35 and appeared to be men, he said.

Numerous vehicles came and went from the house, but Flores thought a pair of families, not human smugglers, probably lived there.

"This is a substantial amount of officers here," he said, looking at the throng of police. "I mean, this isn't south Phoenix."

Later in the day, Sheriff Joe Arpaio said the raid was proof his agency targets the side of illegal immigration that can get violent and dangerous.

His critics have assailed him for ordering deputies to use minor traffic violations to find suspected illegal immigrants.

"This was a hostage situation," Arpaio said. "Fortunately, we got there before there was any violence."