White powder was found in an envelope today at a TriBeCa elementary school and another suspicious piece of mail was discovered at a school on the lower east side, authorities said.

At least two adults needed to be decontaminated at PS 234 on Greenwich Street after they opened an envelope containing the mysterious powder at 1:30 p.m, police said.

At 4 p.m. at the New Explorations into Science, Technology and Math High School on Columbia Street there were reports of receiving an envelope, said a spokeswoman for the Department of Education.

That envelope was not opened, but the police were called to the school, officials said.

There were no injuries reported at either incident.