In a statement, ICRO described it as a big injustice to the people of Bahrain who consider the senior cleric as a source of hope for a better future in which their human and social rights are respected.
The statement added that by such measures, the Manama regime will not be able to repress the Bahraini nation’s efforts to regain their rights.
ICRO also called on international rights bodies and Islamic organizations to stand up to the blatant injustice and prevent it from becoming a norm in the conduct of the region’s despotic regimes.
Bahrain said Monday that the citizenship of Sheikh Qassem has been revoked, accusing him of sowing sectarian divisions.
The move has drawn widespread criticism internationally.
It came days after a regime’s court issued an order earlier suspending the activities of Bahrain’s main opposition bloc, Al-Wefaq National Islamic Society, on charges of "terrorism, extremism, and violence”.
Bahrain, a close ally of the US in the Persian Gulf region, has been witnessing almost daily protests against the ruling Al Khalifa dynasty since early 2011, with Manama using heavy-handed measures in an attempt to crush the demonstrations.
Scores of Bahrainis have been killed and hundreds of others injured and arrested in the ongoing crackdown on the peaceful demonstrations.