D.C. officials said this evening that the schools that received letters containing a suspicious powder will open on time Friday.

The schools include: Ballou High School in Southeast, Hamilton Junior High School in Northeast, Johnson Middle School in Southeast, Lafayette Elementary School in Northwest, Martin Luther King Elementary School in Southeast, M.C. Terrell Elementary School in Southeast, Phelps High School in Northeast, Powell Elementary School in Northwest and Ronald H. Brown Middle School in Northeast, and School Without Walls High School in Northwest.

“We plan to open all schools tomorrow unless otherwise directed by MPD or the FBI,” said DCPS spokesperson Frederick Lewis.

Several of the schools were evacuated, but no students were treated for illness and site tests found nothing toxic, according to D.C. Fire and EMS spokesman Pete Piringer. One school administrator who asked not to be named because she was not authorized to discuss the matter, said the substance was identified as “potato starch.”

At least six of the letters, mailed from Dallas, contained white powder and a letter with the words “AL AQEDA-FBI,” according to a bulletin released by the Washington Regional Threat and Analysis Center in the District.

The letters were sent with typed address labels, said the bulletin, which said they are identical to letters received by District schools in October 2010.