Abdulla al-Shamlawi, a defence lawyer, said that the three men had been released without bail being demanded.
He said the lack of bail showed that the government wanted to "calm down the situation".
"The release is a positive step by the government because the situation in the streets could get worse," al-Shamlawi said.
Activists 'to be charged'
The interior ministry issued a statement saying that the three activists would be charged with "promoting change to the political system through illegitimate means, inciting hatred of the political system, agitation and harming the public interest".
Mohammed Bu-Humod, an interior ministry spokesman, said the government had "documented pictures and recorded speeches made by the accused during Ashura which aimed at splitting national unity".
|Shias in Bahrain have long complained of a|
lack of political power despite reforms [AFP]
During the Shia Muslim commemoration of Ashura, al-Khawaja made a speech that criticised the government and Haq ran a street kiosk that gave a digital display on various issues, including victims of Bahrain's unrest in the mid-1990s.
Haq is an opposition movement that wants democratic reform and greater rights for the Shia Muslim population in Bahrain.
The government refuses to recognise the group, and considers both it, and the Bahraini Centre for Human Rights, to be illegal organisations.
Shias make up about 60 per cent of Bahrain's population, but the ruling family is Sunni Muslim.
Shias have long complained of discrimination and a lack of political power.