Protesters hold a banner with the faces of political prisoners during a protest in the town of Awamiyah on March 3.
Government forces have attacked Saudi Arabian peaceful demonstrators in the east of the oil-rich kingdom.
Protesters took to the streets of Awamiyah town in the Eastern Province late on Wednesday, witnesses said.
During the protest, people demanded respect for human rights and the release of political prisoners in the country.
At least two demonstrators were arrested after breaking up the rally, according to reports.
The Eastern Province has been the scene of anti-government protests in recent months.
Saudi Arabia, a key US ally in the Middle East, is an absolute monarchy that does not tolerate any form of dissent.
Protest rallies and any public displays of dissent are considered illegal.
The government has become increasingly nervous about the protests that have taken the Arab world by storm, toppling the Egyptian and Tunisian leaders, and which reached Bahrain, Yemen and Libya.