The men assembled during a funeral procession that followed Friday prayers in the mosque of Shaikh Sulaiman al-Rajhi in the al-Rabwa neighbourhood, the Al-Riyadh daily said on Saturday.
"As the participants in the procession were chanting Allahu Akbar (God is Great), some (who joined them) behaved mobbishly. Security men intervened and a number of people were detained," the paper quoted interior ministry spokesman Mansur al-Turki as saying.
The paper said that less than 20 people were arrested, of whom half were released the same day.
The Islah (reform) television channel which belongs to London-based Saudi dissident Saad al-Faqih had reportedly called for
a gathering near the Rajhi mosque after Friday prayers.
Anti-government demonstrations called for last month by al-Faqih, who heads the Movement for Islamic Reform in Arabia (MIRA), were thwarted as Saudi security forces deployed en masse in Riyadh and Jedda, detaining 14 people.
At the end of October 2003, security forces detained more than 70 people in several parts of the country to head off protests called by MIRA.
MIRA called for demonstrations
in Saudi Arabia last month
This followed the detention of 271 people who took part in a protest in Riyadh the same month, also called by the dissident Islamist group in defiance of a ban on street protests in the kingdom.
The bulk of those arrested were later reported to have been freed.