Two girls confessed to hand-delivering letters containing a white powder to two town residences in what Darien police said Tuesday evening was a hoax.

"Darien police are confident that the investigation will be limited to the two occurrences reported and that there is no evidence to suggest that any person is in any danger as a result of these incidents," according to a statement released Tuesday evening.

The first letter was reported Monday and the second Tuesday morning. Numerous law enforcement and other agencies responded to the incidents, including the Darien police, Connecticut State Police, the FBI, the Stamford Police Bomb Squad, the state Department of Environmental Protection, the Darien Fire Marshal's Office, the Darien Fire Department and Darien EMS, a police statement said.

The confessions came after members of the Darien Police Detective and Youth divisions and the school resource officer met with two female juveniles and their parents regarding the incidents. The two females turned themselves in to the police. Charges have not yet been filed, Detective Mark Cappelli said. He added that if police arrest the girls, it will be via warrant.

Cappelli didn't have the girls' ages before press time.

Police did not name the girls because they are juveniles. They told police the residences they targeted were chosen randomly and that they had no connection to them. The girls told police the powder was a "nontoxic food product," but it would still be tested for verification, police said.

The case will be discussed with the State's Attorney's Office and possibly be referred to Juvenile Court, said police.

On Monday afternoon, Darien and state police and the FBI responded to a Tokeneke residence on a report of a threatening letter containing a suspicious white powder.

The powder was removed from the home about 7:30 p.m. by the State Police Emergency Services Unit, according to Darien police.

On Monday night, police said definitive identification of that substance could take up to five days.

In that case, nine people, including a Tokeneke constable, were confined to the residence to reduce the chance of exposure to others, according to police. One of the residents called the constable to report the letter and white powder, police said. Later Monday evening, because those people appeared to be suffering no symptoms, the FBI and members of the State Police Special Response Unit instructed them to "self decontaminate" by changing their clothes and washing their hands.

On Tuesday morning, Darien police and federal and state authorities investigated the second incident, which occurred on Rainbow Circle, also in the Tokeneke section of town, after a resident reported receiving a letter on Saturday that contained a suspicious white powder, according to police. Police did not provide the time of the report made on Tuesday or the exact address of the home.

The resident had shown no symptoms indicative of exposure to a biological toxin, according to police.

The resident, who initially dismissed the letter as a prank, contacted police after Monday's incident was reported, according to police.

mspicer@bcnnew.com;203-330-6583; @Meg_DarienNews