A Saudi-based rights group has urged the kingdom to release 100 Shiite protesters it said were arrested in its Eastern Province last week, some of whom it says have been tortured.
"During the peaceful protests last week in the Eastern Province, the protesters were arrested," Human Rights First Society said on Wednesday.
The organisation called for "the immediate release of these peaceful demonstrators and a full investigation into the accusations of physical and psychological torture to which some of the detainees were subjected".
Ten people were injured in clashes on March 18 between demonstrators and police in Omran, a city in the Eastern Province which is home to the vast majority of Saudi Arabia's estimated two million Shiites, according to a witness.
At least 2,500 people demonstrated in Awamiya and about 1,000 each in Safwa and Al Rabeeya, all near Qatif City, where Shiites have been holding daily demonstrations, witnesses said.
Demonstrators have shouted slogans in support of Bahraini Shiites and demanded the release of nine Shiites jailed without trial in Saudi Arabia since 1996.