Iraqi Shiite cleric Moqtada al-Sadr called for a boycott of the upcoming Formula 1 race in Bahrain over the kingdom's continued crackdown on dissidents, in a statement released on Thursday.

"I call on all honest sportsmen not to participate in that race ... and to support the Bahraini people in their rejection of holding this race," the cleric, who heads the powerful Sadr movement, said in a statement released by his office in the Shiite holy city of Najaf.

"Holding the race in that country supports killing, oppression and the violation of the Bahrain people's freedom," Sadr, the anti-American cleric, said.

The sport's governing body, the FIA (Federation Internationale de l'Automobile), and commercial rights holder Bernie Ecclestone announced last week that Bahrain Grand Prix will go ahead on April 22, despite the kingdom's continued crackdown on demonstrators.

Witnesses said on Thursday that Bahraini police fired shotguns and tear gas to disperse overnight demonstrations outside the capital Manama.

The Bahrain Grand Prix was cancelled last year in the wake of the Shiite-led uprising and the brutal government crackdown that followed in which 35 people were killed, according to an independent commission of inquiry.