Shouting anti-government slogans, demonstrators on Friday called for the down fall of Al Khalifa dynasty, which has ruled Bahrain for more than four decades.
The rally was organized by the country’s main opposition group, al-Wefaq.
The protesters also called on the international community to stand by the Bahraini people.
The massive rally came one day after hundreds of Bahraini women staged a protest rally in the village of Maqsha to condemn the imprisonment of female doctors, teachers and other demonstrators jailed for taking part in anti-regime protests earlier this year.
On Thursday, a military court in Bahrain sentenced 20 medics, who treated anti-government protesters, to up to 15 years in prison each, after convicting them of conspiracy to overthrow the regime.
In a separate case, the special security court sentenced a protester to death over the alleged killing of a policeman.
One day earlier, the same court had upheld the life sentences handed to eight opposition leaders convicted of having vital roles in the anti-government protests in the country. It also upheld sentences of up to 15 years on 13 other activists.
Thirty-two others were handed 15 years behind bars earlier this week for taking part in anti-regime protests.
The harsh sentences handed to dissidents have drawn international criticism. The United Nations human rights office said on Friday that the trials failed to meet international standards of transparency as the accused had been allowed limited access to lawyers.
“For such harsh sentences to be handed down to civilians in a military court with serious due process irregularities raises severe concerns,” said Rupert Colville, spokesman for the UN High Commissioner for Human Rights.
“We even hear of people calling their families a day before the hearing to appoint a lawyer,” said Colville.
The rights body also criticized Manama for refusing to investigate reports of torture and prohibited recorded proceedings.
The World Medical Association has also condemned as “totally unacceptable” the jail terms imposed by a military court, while the World Health Organization said medical personnel should never be punished for doing their duty and treating all patients.