Between 100 and 200 protesters gathered outside the Information Ministry in Bahrain's capital Manama on Tuesday, with a larger protest was planned for later, DPA reported.
The protesters - opposition politicians and activists - have vowed to keep up their call for the government to step down, despite last week's partial cabinet reshuffle.
Shiite Muslims, who have complained of discrimination by the ruling Sunni minority, also took part in the protest. More than 70 per cent of Bahrain's population is Shiite.
Thousands are expected to take part in march from Salmaniya Hospital to Lulu Square, the focal point of anti-government protests since February 14.
A new Shiite minister, Nizar al-Mahalla, replaced the former health minister on Tuesday, who had been accused of ordering ambulances to refrain from assisting injured protesters. Seven people have been killed in clashes between protesters and security forces.