Two people were seriously injured and eight others arrested when the anti-riot police broke up a demonstration in Yemen's southern province of Lahj.
The demonstration, which started early Tuesday night in Lahj's capital, Hawta, for a fourth straight day turned violent amid continuous protests by motorcyclists against oppression they claimed exercised by traffic authorities on them.
Rioting was seen during the protest with police shooting bullets and tear gas and pursuing and arresting rioters across the capital.
Stores closed down after their owners feared they would be attacked and looted.
Rioters also closed Sana'a-Aden highway by burning tires and putting rocks in it.
Southern motorcyclists protested holding their motorbikes by the province traffic authority under a cabinet decision calling for numbering motorbikes and drive licenses.
They say they can't afford fees for the process as they have dependants, refusing to stick to the decision.
Lahj is one of the south provinces experiencing unrest by those seeking better rights and the fans of southern anti-government movement.
Protestors attacked the people and public properties, clash with police and sometimes commit terrorist attacks.
Scores were killed this year, including 89 people and soldiers in Dhale, in rioting, according to official reports.