Is Ashtanga Yoga Religious Indoctrination?

A group of parents in the Encinitas School District in California believe the practice of this form of yoga which involves breath control and a series of yoga postures, represents religious indoctrination. An elementary school in the Encinitas district allows its students to practice Ashtanga yoga for thirty minutes twice a week. The controversy is interesting. Here is one story about the it and here is another.