A policeman in Bahrain has been arrested after a video showing him hitting a resident of a Shiite village was posted online, the interior ministry said on Tuesday.
"The video shows the policeman slapping a citizen in Aali, a local village, on December 23rd, 2012," the ministry said in a statement, adding that the officer was detained on Monday.
"Such behaviour is unacceptable for any police officer and ... a legal investigation has been launched. The case was then referred to the police court," the statement added.
It said the arrest follows Bahrain's "keenness to equally subject all those who violate human rights to the just penalty, as seen fit by the court of law."
Al-Wefaq, the main opposition grouping in the tiny Gulf kingdom, denounced the incident, saying the policeman "slapped the citizen and insulted him."
In the face of such repeated incidents, the people "stick to their legitimate demands... for democratic reforms" in Sunni-ruled Bahrain, it warned.
Since February last year, Bahrain has been shaken by Shiite-led opposition protests that the authorities accuse of being exploited by Shiite Iran across the Gulf.
At least 80 people have died since the start of the unrest in February 2011, according to the International Federation of Human Rights.
The opposition insists that the premier stand down and that the government be headed by the leader of the elected majority in parliament.