A google map showing the locations where 7 letters containing a suspicious white powder were found on May 8, 2012

NORTH TEXAS (CBSDFW.COM) – Authorities now say that at least 8 letters containing a suspicious white powder have turned up in North Texas Tuesday.

The letters have been found in Dallas, Irving, Garland, Grand Prairie and Mesquite. Six of the eight locations are connected with Head Start of Greater Dallas, the other locations are a similarly-named day care and a church.

Irving authorities say the letters were corn starch while Mesquite says the substance was a sweetener. The others have not revealed what the powder is.

The first letter was discovered around 3 p.m. Tuesday at the Pierce Early Childhood Center. Irving ISD press secretary Billy Rudolph says the letter was addressed to the school’s principal.  Rudolph says since the school was close to released, and as the secretary was the only one exposed, the school was not evacuated.  The building was secured by Irving Haz-Mat crews.

The second letter in Irving was found at Clifton Early Childhood Center roughly an hour later.  Rudolph says Irving Police are investigating that school as well.

The Early Childhood Centers are a joint program with Head Start and Irving ISD.  The school district will have each of their principals return to their buildings Tuesday evening to search mail sent to the school for any possibly suspicious letters.

The third letter in Irving was discovered around 5:15 p.m. Tuesday evening at the West Irving Head Start center on Jackson Street.  It is not connected to Irving ISD, or to Head Start of Greater Dallas, but is across the street from Davis Elementary School.

In Garland, a worker at the West Garland Head Start on Walnut Street found a letter around 3:30 p.m. Tuesday afternoon.  That letter has already been determined to be non-threatening, and the scene was cleared.  Garland Police spokesman Joe Harn said the few remaining children at the facility were picked up by family members.

Late Tuesday, Harn said a white powder letter was also sent to Anderson Childcare Group Center at 625 E. Ave. B downtown. That location is also affiliated with the HeadStart program.

Harn asid the department has a mobile test unit, procured by a grant obtained just after 9/11. The unit was dispatched, and none of the schools had to be evacuated.

In Grand Prairie a letter was found at Lighthouse Baptist Church on Northeast 27th Street.  In addition to the powder, a threatening note was found inside the envelope addressed to the church.

The fifth letter turned up at the Jerry R. Junkins Head Start in Mesquite after school had been let out for the day.  It too had a threatening note inside.

Another letter later turned up at a Head Start center in Dallas, that center is connected to the Lakewest Family YMCA on Goldman Street.

Head Start of Greater Dallas spokeswoman Deneeco Young said the staffs at their locations acted quickly on dealing with the letters.  She said children were calmly evacuated from the areas.

Postal Service’s Amanda McMurrey said the powder in the letters is not believed to be harmful.  The Dallas Fire Department Haz-Mat team reported the Mesquite and Dallas letters contained an artificial sweetener.  Irving is reporting their three letters contained corn starch.

The FBI and U.S. Postal Inspectors are working with local departments in each of the cities on their investigations.