Children play outside Winterberry Charter School in Anchorage, Alaska, Wednesday, March 30, 2016. Three first-graders in Alaska's largest city plotted to kill a fellow student with silica gel packets that the girls believed was poison and have been disciplined but not charged with any crime, authorities said Wednesday.

ANCHORAGE, Alaska — Three first-graders in Alaska’s largest city plotted to kill a fellow student with silica gel packets the girls believed was poison, authorities said Wednesday.

The three have been suspended but not charged with any crime.

Parents of the 32 first-graders attending Winterberry Charter School in Anchorage got word of the plot in a March 22 e-mail from the principal. The three female students acknowledged they planned to poison a female classmate, school district officials said.

A school resource officer interviewed the girls and determined they intended to harm to the other girl, but charges will not be filed, police said. Silica gel packets, which soak up moisture, are not poisonous.

“I’m not sure what we could criminally charge first-graders with,” police spokesman Jennifer Castro said, noting no parents or other adults were involved. “What ended up happening was the officer took each one of them individually, had a very a serious talk with all of them.”

Administrators and school district psychologists talked to the girls to see if they understood what they were trying to do, whether it was a prank gone wrong, or if they actually meant to hurt their classmate, district spokesman Heidi Embley said.

“All of these things are being discussed, especially since it’s such a young age,” she said.

Police say the plot emerged from an ongoing feud but did not release any other details. Two other first-graders told school officials about the plan.

The two students reported to administrators the plan involved using the packets from the girls’ “lunchtime seaweed to poison and kill another student,” Principal Shanna Mall wrote in the e-mail.

Police left discipline up to the school district. The e-mail said it entailed “significant consequences.”

Embley said she couldn’t release further details.

But Mall told Anchorage television station KTUU the students were suspended.

Asked if the school was getting calls from concerned parents or hearing from worried students, Embley said there was “nothing significant.”

The school is addressing any concerns directly with parents or students.