Violent demonstrations are being reported in the Libyan city of Benghazi.
Witnesses say the protests were triggered by the arrest of a lawyer who is an outspoken critic of the government.
The lawyer was later said to have been released, but the demonstrations reportedly continued early on Wednesday.
Pro-democracy protests have swept through several Arab countries in recent weeks, forcing the leaders of Tunisia and Egypt from power.
The BBC reports there is no independent confirmation of the protests in Benghazi, but eyewitnesses say that at one stage about 2000 people were involved.
They say stones were thrown at police who are said to have responded with water cannon, tear gas and rubber bullets.
Later, state television showed pictures of several hundred people in Benghazi voicing their support for the government.
The government has so far not commented on events in the city.
The Middle East has seen a wave of protests fuelled by discontent over unemployment, rising living costs, corruption and autocratic leaderships.
They began with the overthrow of Tunisia's leader, Zine al-Abidine Ben Ali, in January. Last week, Egyptian president Hosni Mubarak resigned.
In recent days there have also been anti-government demonstrations in Yemen, Bahrain, and Iran.