The government in Bahrain is reported to have begun a dialogue with opposition groups demanding political reform.
The information affairs authority said a process of dialogue was underway between the crown prince and political groups.
Protesters have taken over Pearl Square in the capital, Menama after police pulled out.
Troops in tanks and armoured vehicles earlier withdrew from the square, which they had taken over on Thursday after riot police staged a night-time attack on sleeping protesters who had camped out there, killing four people and wounding 231.
The crowds in Pearl Square soon swelled into the tens of thousands, celebrating a triumph for the mostly Shia protesters who took to the streets on Monday, inspired by popular revolts that toppled leaders in Egypt and Tunisia.
The authorities had been determined to prevent protesters from turning Pearl Square into a base like Cairo's Tahrir Square, the heart of a revolt that ousted Egypt's Hosni Mubarak.
Around 80 people were taken to Salmaniya hospital after being affected by teargas or hit by rubber bullets, a doctor said. He said the hospital was full and did not have enough oxygen to deal with the rush of casualties.
More than 60 people were already in the hospital with wounds sustained yesterday when security forces fired on protesters as they headed to Pearl Square, then still in military hands.
Bahrain's crown prince called for a national day of mourning ‘for the sons we have lost’, the state news agency reported.
Crown Prince Salman bin Hamad Al Khalifa, Deputy Supreme Commander of the Armed Forces, called for calm, asking citizens to unite and cooperate with all political forces in the country.
‘I stress, once more, that our duty is to preserve security and stability, to ensure that there is no discord and that the situation does not worsen,’ he said in a statement.
He had earlier announced that troops had been ordered off the streets and that police would keep order.
But people power proved too strong in Pearl Square.
Some people kissed the ground in joy or started praying.
Yesterday, King Hamad bin Isa al-Khalifa offered a national dialogue with all parties to try to end the turmoil in which six people have been killed and hundreds wounded.
Protests continue in Yemen
At least five anti-government demonstrators have been killed in Yemen during protests demanding the immediate resignation of President Ali Abdullah Saleh.
Meanwhile, tens of thousands of supporters of President Saleh have also held a rally in the country's second biggest city, Taiz.
Supporters and opponents of Yemen's President Ali Abdullah Saleh fired shots in the air during rival demonstrations in Sanaa.
Eight protesters were hurt and a witness said one died from a bullet wound in the neck as he was taken to hospital.
But a medical source said he was admitted to intensive care and had stabilised. The Interior Ministry said no one was killed.
Morocco braces for nationwide protest
Local media in Morocco has said that they are expecting planned political protests, amid concerns of possible unrest in the wake of the popular revolts that recently toppled regimes in Tunisia and Egypt.
Young Moroccans recently called for the kingdom-wide Sunday demonstration demanding broad political reforms, gathering several thousand supporters on the social networking site Facebook.
