Manama, Bahrain (CNN) -- Thousands of Bahrainis hit the streets again to vent their anger at the Arab nation's government on Friday, an opposition source said, days after the justice ministry warned against "any type of activities that could affect the security or harm the national peace and safety."
Sanabis, just west of the capital, Manama, was the hub of the day's biggest demonstrations. Thousands marched late Friday in the suburb, an opposition source said.
Earlier, about 1,000 people had gathered to mourn Zainab Ali Altajir, a 69-year-old woman who died Thursday after allegedly inhaling tear gas fired by authorities as they clashed with protesters, an opposition figure said.
In a statement on Bahrain's interior ministry website, the government denied that the woman died from tear gas inhalation, saying she had chronic heart disease and died of natural causes.
Later Friday, the opposition source said, about 1,000 demonstrators congregated in Manama to remember Salman Abu Idrees, a 63-year-old who had been missing since mid-March. Images of Idrees' body showed his injuries -- including one that the source said was a rubber bullet in the stomach.
There was no indication whether government forces, including police, confronted or obstructed those demonstrating Friday. Bahraini government officials could not immediately be reached for comment.
The protests came the same day that Bahrain celebrated the World Motor Sport Council's decision to reinstate the Bahrain Grand Prix into the Formula One racing season.
Bahraini and racing officials lauded the return of the race as a sign of reconciliation, though signs that the turmoil is not over remained.
Wednesday's lifting of emergency laws, imposed in mid-March and allowing a crackdown on political leaders and journalists, is thought to be an effort to signal an end to months of unrest stemming from the Arab Spring, a wave of anti-government protests that started in Tunisia and have since roiled several countries in the Middle East and North Africa, including Egypt, Syria, Yemen and Bahrain.
Since the beginning of the turmoil in Bahrain, about 30 people have been killed, according to figures from the government, opposition figures and human rights groups. Opposition and human rights groups say more than 1,000 have been detained.
Even after the lifting of emergency laws, the government has continued its crackdown on the country's major Shiite political opposition movement.
The kingdom also filed charges against four top opposition leaders in a move that could weaken the country's Wefaq party, according to two opposition sources. This came as King Hamad bin Isa Al Khalifa appealed for dialogue, saying that talks with opposition groups are scheduled to begin in July.
On Friday, Bahrain's Crown Prince Salman bin Hamad Al-Khalifa and Foreign Minister Sheikh Khalid bin Ahmed bin Mohammed Al Khalifa met with U.N. Secretary-General Ban Ki-moon, according to a statement from the United Nations. The world body's leader called on Bahrain's government "to uphold international human rights norms ... and welcomed the commitment and assurances made by the Crown Prince in this regard."
Ban "welcomed the lifting of emergency laws and the decision ... to call for a national dialogue," the U.N. statement said. "He expressed hope that such a dialogue would be genuine, meaningful and inclusive and respond to the legitimate political, economic and social aspirations of all Bahraini people."
CNN's Jenifer Fenton contributed to this report.