Protests calling for democratic change have erupted in recent days in Bahrain, Yemen and Libya following popular uprisings in Tunisia and Egypt that led to the ouster of long-time rulers there.
Pillay stressed that lasting social stability could only be built on the foundations of the freedoms of expression and of peaceful assembly, adding that Bahrain, as a State party to the International Covenant on Civil and Political Rights, must fully respect its human rights obligations.
OHCHR had been working on establishing a dialogue with the authorities since the political crackdown that began in the country in August 2010.
"I have been urging the authorities to curb the excesses of the security apparatus and to undertake serious investigations into allegations of torture and abuse of detention rights of hundreds of political and human rights activists," said the High Commissioner.