Anti-government protests inspired by popular revolts that toppled rulers in Tunisia and Egypt are gaining pace around the Middle East and North Africa despite political and economic concessions by nervous governments.
Clashes were reported in tightly controlled oil producer Libya, sandwiched between Egypt and Tunisia, while new protests erupted in Bahrain, Yemen and Iran on Wednesday.
The latest demonstrations against long-serving rulers came after U.S. President Barack Obama, commenting on the overthrow of Egyptian President Hosni Mubarak, declared: The world is changing...if you are governing these countries, you've got to get out ahead of change, you can't be behind the curve.
With young people able to watch pro-democracy uprisings in other countries on satellite television or the Internet, and to communicate with like-minded activists on social networks hard for the secret police to control, governments across the region have grounds to fear contagion.
Hundreds of opponents of Libyan leader Muammar Gaddafi, in power since 1969, clashed with police and government supporters in the eastern city of Benghazi overnight, a witness and local media said.
Reports from the port city, 1,000 km (600 miles) east of the capital Tripoli, said protesters armed with stones and petrol bombs set fire to vehicles and fought with police in a rare outbreak of unrest in the oil-exporting country.
The riot in Libya's second city was sparked by the arrest of human rights activist Fethi Tarbel, who has worked to free political prisoners, Quryna newspaper said.
Gaddafi's opponents used the Facebook social network to call for protests across Libya on Thursday.
In a possible concession to the protesters, Libya will free 110 members of the banned militant organisation the Libyan Islamic Fighting Group from Tripoli's notorious Abu Salim prison on Wednesday, another human rights activist said.
POLITICAL, ECONOMIC CONCESSIONS
In Yemen, a 21-year old protester died from gunshot wounds after fierce clashes broke out between police and demonstrators in the southern port town of Aden, his father said, as unrest spread across the Arabian Peninsula state.
Mohammed Ali Alwani was among two people hit as police fired shots into the air to try to break up around 500 protesters.
In the Yemeni capital Sanaa at least 800 anti-government protesters marched against President Ali Abdullah Saleh, a U.S. ally in the fight against al Qaeda.
In power for more than 30 years, Saleh has pledged to step down when his term expires in 2013 and offered dialogue with the opposition, but radical protesters are demanding he go now.
In Bahrain, protesters poured into the capital of the Gulf island kingdom, Manama, for a third successive day to mourn a demonstrator killed in clashes with security forces on Tuesday.
The emirate has a history of protest over economic hardship, the lack of political freedom and sectarian discrimination by the Sunni rulers against the Shi'ite majority.
Some 2,000 protesters demanding a change of government were encamped at a major road junction in Manama, seeking to emulate rallies on Cairo's Tahrir Square that toppled Mubarak.
In Iran, supporters and opponents of the hardline Islamic system clashed in Tehran during a funeral procession for a student shot at an anti-government rally two days ago, state broadcaster IRIB reported.
Both sides claimed Sanee Zhaleh was a martyr to their cause and blamed the other for his death.
Monday's rallies in Tehran and several other Iranian cities were the first staged by the Green pro-democracy movement since security forces crushed huge protests in the months after President Mahmoud Ahmadinejad's disputed 2009 re-election.
Rulers in several countries, drawing lessons from events in Tunisia and Egypt, have announced political changes and moved to cut prices of basic foodstuffs and raise spending on job creation in efforts to pre-empt spreading unrest.
Algerian President Abdelaziz Bouteflika promised to lift a 19-year-old state of emergency soon and has acted to reduce the cost of staple foods in the North African oil and gas exporter.
Authorities deployed an estimated 30,000 police in Algiers on Saturday to prevent a banned pro-democracy march. Several hundred protesters defied the ban and dozens were detained.
A coalition of civil society and human rights groups and an opposition party vowed afterwards to demonstrate every Saturday until the military-backed government is removed.
Morocco, where the main banned Islamist opposition movement warned last week that autocracy would be swept away unless there were deep democratic reforms, announced on Tuesday it would almost double state subsidies to counter an increase in commodity prices and address social needs.
Syria, controlled by the Baath Party for the last 50 years, released a veteran Islamist activist on Tuesday after he went on hunger strike following his arrest 11 days ago for calling for Egyptian-style mass protests, human rights activists said.
Jordan's King Abdullah has sacked his prime minister and appointed a new government led by a former general who promised to widen public freedom in response to anti-government protests.
Countries with oil and gas wealth such as Saudi Arabia and Algeria appear better placed than poorer countries like Egypt and Tunisia to buy social peace.