Ayatollah Mahdi Hadavi Tehrani's answer to the above question is as under:
It is permissible to exercise Taqiyah wherever the conditions of Taqiyah are met, be it reconciliatory or out of fear. In some circumstances, exercising Taqiyah becomes obligatory.
Given that you are afraid lest they should harm you, it is permissible for you to do Taqiyah and fold your hands during prayer. Of course, you should note that folding hands in prayers has neither been considered as a recommended act nor as an obligatory one.