The majority-Catholic Philippines told Muslim teachers Tuesday to remove their veils inside classrooms, in part to promote better relationships between teachers and pupils.
Education Secretary Armin Luistro said the move was part of reforms to make schools more sensitive to religion.
Muslim schoolgirls will still be allowed to wear the veil or "hijab" on campuses as well as "appropriate clothing" in gym class, according to the order, a copy of which was obtained by AFP.
But while female Muslim schoolteachers can wear the veil outside class, they are told to remove the veil during lessons so they can interact better with students.
"Once the (teacher) is in the classroom, she is requested to remove the veil," the order said.
Having Muslim female teachers remove their veils allows for "proper identification of the teachers by their pupils, thus promoting better teacher-pupil relationship", it said.
Being able to see the teachers' faces also helps in teaching language, where "lip formation" plays a role in pronouncing certain letters, it said.
The government's Office of Muslim Affairs said it agreed with the education department's measures, although it had not yet received a copy of the order.
Roque Morales, an adviser to the office, said that while he did not know how many Muslim Filipinas were working as teachers, the practice of wearing veils is widespread in the southern Philippines.
"You would almost see it everywhere," he told AFP.
He said the office had so far not received any complaints from Muslim teachers.
The office said that Muslims make up about 15 percent of the Philippine population, mostly based in the southern regions which they consider their ancestral home.
Armed separatist Muslim insurgencies have been a persistent problem for the Philippines since the 1970s, and the government has tried to accommodate the Muslim minority by respecting many of their practices.