Praying towards a Direction other then the Qiblah
Question:
If a congregation prayed towards a direction other then the Qiblah and they did not know its exact direction, must they repeat the prayer?
Answer:
If they were in the desert, and they exercised their judgement regarding where they believed the Qiblah to be, there is nothing for them to make up. However, if they were in a town or village, then they must make up for it, because it was possible for them to ascertain from those around them the direction of the Qilbah.
Source:
Shaykh `Abdul-`Azeez Bin Baz
Fatawa Islamiyah Vol. 2 Page 252