Mohammed Bu Humayed and Abdullah Burashid, who were arrested along with nine other Bahraini youths from the same village, had their detention extended for 15 days pending further investigation.
The arrests came shortly after the men took part in marches commemorating Ashura, which marks the martyrdom of Imam Hussein (AS).
A number of the participants in that march reportedly wrote the first name of the Bahraini monarch, Hamad bin Isa Al Khalifa, along the chosen route.
Those who took part in the Ashura procession walked over the handwritten insignia, prompting the arrests and subsequent allegations.
The past week alone saw over a dozen Bahrainis summoned or detained in connection with the annual Ashura commemorations.