There were no more immediate details on the blast in Diraz village, which is home to Ayatollah Isa Qassim and has been a flashpoint for violence.
Activists from the country's Shi'ite Muslim majority accused the Sunni-led authorities of using excessive force to intimidate the sect and its spiritual leader.
A U.N. human rights chief has urged an investigation into the raid, which he called a crackdown on dissent.
Qassim faces expulsion from the kingdom after authorities revoked his citizenship last year for alleged links to Iran and fomenting violence, charges he has denied.
The raid and subsequent arrests increased tensions in Bahrain, days after U.S. President Donald Trump said Washington's relationship with the kingdom would improve.