Dozens of Saudi men gathered outside the interior ministry in Riyadh on Sunday undeterred by heavy police presence, to demand the release of jailed relatives two days after King Abdullah offered $93 billion in handouts but gave no political concessions.
Protests are banned in Saudi Arabia. A Reuters witness could not get close to the heavily guarded ministry but saw dozens of men in traditional white robes gathered outside while a large number of police and security forces watched on.
There were at least 50 police cars surrounding the ministry.
"We have seen at least three or four police vehicles taking people away," said an activist there who declined to be named.
"Security have arrested around 15 people. They tried to go into the ministry to go and ask for the freedom of their loved ones," the activist said.
The spokesman for the interior ministry could not immediately be reached for comment.
Saudi Arabia, a U.S. ally, has escaped the mass uprisings that have rocked the Arab world but dissent has built up as unrest has spread in neighbouring Yemen, Bahrain and Oman.
Web activists had scheduled March 11 as the first day for mass protests around Saudi Arabia in favour of democratic government and a constitutional rather than absolute monarchy.
But a religious ruling banning demonstrations and a heavy police crackdown appeared to have intimidated most potential protesters.
Shi'ites have staged marches in the Eastern Province, where most of the kingdom's oil fields are located.
Saudi Arabia's minority Shi'ites complain of discrimination, saying they often struggle to get senior government jobs and benefits available to other citizens.
King Abdullah on Friday offered massive social handouts and boosted his security and religious police forces.
But in a rare televised address to the nation, he did not give concessions on political rights in a country where the public sphere is dominated by the Saudi royal family, political parties are banned and there is no elected parliament.