The downtown square was the focus of weeks of Shiite-led protests against the Gulf nation's Sunni rulers earlier this year. Witnesses in the tiny island kingdom said there were no immediate reports of casualties among the hundreds of opposition supporters who took their grievances to the streets for the first time since martial law was imposed more than two months ago.
The country's security force moved against the protesters shortly before Formula One's governing body deemed the kingdom safe enough to host the Bahrain Grand Prix in October.
The annual F1 race has been Bahrain's most profitable international event since 2004, when the nation became the first Arab country to stage the Grand Prix. Bahrain organizers insisted they are ready to host the race this year despite the deadly crackdown. The season-opening March auto race was postponed because of the political unrest.
Also Friday, thousands of mourners gathered at a cemetery in the capital, Manama, to bury a protester who died in a hospital earlier in the day of injuries from a demonstration in March.
The death of 63-year-old Salman Abu Idris raised to at least 31 the number of people killed since the campaign for greater rights and freedoms began in the Western-allied nation in February.
Bahrain is home to the U.S. Navy's 5th Fleet, and the U.S. has called on its leaders to make reforms in an effort to meet at least some of the protest movement's demands.
The government lifted emergency rule Wednesday, pulling back tanks and soldiers from the heart of the capital. But authorities warned they were not easing pressure on anti-government protesters. Opposition groups called supporters to return to the streets, the first such appeal since the military overran the protesters' encampment at Pearl Square after martial law was imposed in mid-March.
U.N. Secretary-General Ban Ki-moon welcomed the lifting of emergency laws and the king's call for a national dialogue at a meeting in New York late Friday with Crown Prince Salman bin Hamad Al Khalifa, who is also Bahrain's deputy defense chief, and Foreign Minister Khalid bin Ahmed Al Khalifa.
"The secretary-general reiterated his call on the government and security forces in Bahrain to uphold international human rights norms and standards and welcomed the commitment and assurances made by the crown prince in this regard," U.N. associate spokeswoman Vannina Maestracci said.
Ban also reiterated the U.N.'s readiness to assist in promoting a national dialogue, she said.
Bahrain's Sunni rulers invited 1,500 troops from a Saudi-led Gulf force to help suppress the unrest when emergency rule was declared. The Saudi intervention infuriated Iran, the major Shiite power in the Gulf. It underscored the fears of Iran among Sunni-dominated Arab countries, particularly among Gulf Arab leaders. They fear gains by Bahrain's Shiites could provide an opening for expanded Iranian influence on the doorstep of rival Saudi Arabia.
Despite tight security across Bahrain and police reinforcements at checkpoints around the capital, hundreds of opposition supporters from the mostly Shiite populated villages around Manama took their grievances to the streets again and set off to reclaim Pearl Square.
"Instead of rights, every family got a political prisoner. Did the government expect people to stay at home?" said Nabeel Rajab, a leading activist and president of the Bahrain Center for Human Rights. "After almost three months of military rule, the crisis is deeper because every family suffered when the army was sent to solve a political problem."
The emergency rule gave the military wide powers to suppress the Shiite-led demonstrations against the minority Sunni monarchy that has ruled Bahrain for over 200 years.
Hundreds of protesters, political leaders and Shiite professionals like doctors and lawyers have been arrested and tried in a special security court, set up under martial law. Two protesters were sentenced to death.
Just before the emergency rule was lifted, Bahrain's king urged "unity talks" with protest factions beginning in July _ a gesture that fell short of opposition demands for a constitutional monarchy with an elected government. King Hamad bin Isa Al Khalifa's message was in sharp contrast to a Justice Ministry statement calling the demonstrations "criminal acts" and warning that any further challenges will have "consequences."