Abu Amr (may Allah have mercy on him) narrated that he heard Ata' (may Allah have mercy on him) say: A menstruating woman and a woman in a state of major impurity do not undo their plaited hair or their braids, and a menstruating woman may pass through the mosque in case of necessity.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4329