About 50 people in Bahrain have been beaten and arrested by police in the capital, Manama, a human rights activist and other witnesses say.
Witnesses said police hit protesters with batons
Nabil Rajab said police acted to disperse demonstrators who protested outside the king's royal court against the lack of jobs in the Gulf kingdom.
He said among those beaten was Abdulhadi al-Khawaja, the head of the banned Bahrain Centre for Human Rights.
The interior ministry said police acted after being attacked by the protesters.
Its statement said a number of police officers were hurt by the demonstrators who refused a police order to leave the area.
The arrested people were later released, the statement said.