An introductory prayer during a Veterans Day assembly at Morgan City High School last week was inconsistent with a school district policy forbidding mandatory religious activities, St. Mary Parish school officials said Wednesday.

The response came a day after the Washington-based American Humanist Association threatened in a letter to sue the district if it did not agree to omit prayer from future school-sponsored events.

“The district will provide guidance to school principals to preserve compliance to the law while also protecting the constitutional rights of all of our students,” Superintendent Donald Aguillard wrote in an emailed statement.

An 11th-grade student at the school complained to the AHA that students were instructed to stand and bow their heads for a Christian prayer during the mandatory assembly Nov. 11, according to the letter written Tuesday to Aguillard and Morgan City High School Principal Mickey Fabre.

Aguillard said he consulted with St. Mary Parish School Board attorney Eric Duplantis, who determined the prayer — led by an invited veteran — was against district policy.

“Please be assured that we recognize the important responsibility of protecting the constitutional rights of all of our students,” Duplantis wrote Wednesday to Appignani Humanist Legal Center attorney Monica Miller, who represented the student in question.

District policy on school prayer states that voluntary, student-led prayer is not prohibited on campus. But the policy does dictate that “no student attending the school shall be required to participate in any religious activity at school.”

Miller said Tuesday that “the prayer delivered at the Veterans Day assembly was neither student-initiated nor student-led. In this context, an objective observer would inevitably perceive it as a state endorsement of prayer.”

The AHA based its complaint on the First Amendment’s Establishment Clause, which addresses the issue of separation of church and state.

The organization in October filed suit against the Douglas County School District in Highlands Ranch, Colorado, for participating in Operation Christmas Child, a program led by Christian missionary group Samaritan’s Purse.

Through the program, participants send gift-filled shoeboxes to children in developing nations who are then taught about Christianity.

In another AHA suit that made it to litigation, a U.S. District Court judge in November 2013 ordered the Fayette R-III School District in Missouri to prohibit district employees from promoting or participating in student-led prayer gatherings.

The complaint stemmed from weekly Christian “devotional” sessions led by a Fayette High School teacher in her classroom during school hours.

The AHA, which also advocates for removing the phrase “under God” from the Pledge of Allegiance, has about 350,000 supporters nationwide, Miller said. The New Orleans Secular Humanist Association is its sole Louisiana affiliate group.

Follow Lanie Lee Cook on Twitter, @lanieleecook.