By Mohammed Ghobari and Khaled Yacoub Oweis
SANAA/AMMAN (Reuters) - Mass protests spread to the capital of Syria for the first time on Friday and looked closer than ever to driving out the leader of Yemen, nearly four months since unrest erupted across the Arab world.
Fridays, the traditional Muslim prayer day, have been the focus of protests since a Tunisian vegetable seller set himself on fire in December, triggering a wave of unrest that swept away the leaders of Tunisia and Egypt and sparked civil war in Libya.
Protests against Syrian President Bashar al-Assad swept into the capital, Damascus and flared across the country, with demonstrators chanting "God, Freedom, Syria."
In Yemen, a defiant President Ali Abdullah Saleh denounced his opponents as liars and bandits, while urging them to join peace talks that would see him hand over power. Demonstrations across the country were vast but appeared to be less violent than in previous weeks.
In Jordan, at least 20 people were hospitalized after clashes between pro-monarchy youths wielding batons and throwing rocks, and ultra-conservative Sunni Muslims who held a rally at a mosque demanding freedom for detainees.
In Saudi Arabia, where all protests are forbidden and demonstrations are rare, hundreds of Shi'ites in the oil-producing east took to the streets. They carried banners showing solidarity with Shi'ites in neighboring Bahrain, who have faced a crackdown from their Sunni Muslim rulers.
The Arab world's unrest has suddenly weakened the grip of autocrats across the region, few of whom had seemed more secure than Syria's Assad, 45, who inherited the presidency from his father 11 years ago. Their Baath party has run the country under emergency law for nearly five decades, brooking no opposition.
In Damascus, security forces used batons and tear gas to prevent thousands of protesters marching from several suburbs from reaching the main Abbasside Square.
"I counted 15 mukhabarat (secret police) busloads," one eyewitness said. "They went into the alleyways just north of the square chasing protesters and yelling 'you pimps, you infiltrators, you want freedom? we will give it to you'."
A witness who accompanied marchers from the suburb of Harasta said thousands chanted "the people want the overthrow of the regime" and tore down posters of Assad along the route.
On Thursday Assad unveiled a new cabinet, which has little power in the one-party state, and ordered the release of some detainees, a move a human rights lawyer said was a "drop in the ocean" compared with thousands of political prisoners still held.
Rights activists reported protests in Deir al-Zor near the Iraqi border, the coastal city of Banias and the southern city of Deraa. Rights groups say at least 200 people have been killed since the protests began in Deraa last month, when authorities detained teenagers for scrawling revolutionary graffiti.
In Yemen -- a poor and politically fragile country plagued by a powerful regional wing of al Qaeda, a separatist movement in the south and a Shi'ite uprising in the north -- Saleh has offered to step down by 2013 but opponents want him to go now.
"We call on the opposition to consult their consciences and come to dialogue and reach an agreement for the security and stability of the country," he told supporters at a rally.
Yemen's Gulf Arab neighbors have offered to mediate an end to the crisis, but Saleh's opponents have rejected that offer, fearing that talks in Riyadh, long an ally of Saleh, would seek to keep him in office.
Saleh says leaving office immediately would put the country in danger, and he wants to oversee elections himself or give interim power to "safe hands."
Hundred of thousands of people demonstrated against his rule in Sanaa, Aden and Taiz. Clerics and tribal leaders who were once his allies issued a statement saying he must go now , and his relatives in the security forces must be dismissed.
"It's only a matter of days before this regime is over. This revolution cannot be defeated. Our aim is to bring down corrupt family rule," preacher Abubakr Obaid told worshippers near Sanaa University, where protesters have camped out since February.
In Jordan, police used teargas to break up the fighting between supporters of King Abdullah and Salafis, religious ultra-conservatives who follow preachers sympathetic to al Qaeda and had demonstrated to call for detainees to be freed.
"They want us to stop our sit-ins to demand the release of our brothers in prisons. Our demands are peaceful and they wanted to provoke us," Sheikh Abdul Qader Tahawi, who witnessed the clashes, told Reuters.
Saudi Arabia's King Abdullah has promised billions of dollars in social spending to head off unrest spreading to the world's top oil exporter, especially disaffected Shi'ite communities in the east. Last month Saudi troops helped put down demonstrations by Shi'ites in neighboring Bahrain.
Hundreds of protesters took to the streets in Saudi Arabia's Shi'ite center of Qatif for a second straight day on Friday.
"The rally was in a main street in Qatif... They were showing solidarity with the Bahraini people and also calling for the release of some prisoners held for over 16 years without a trial," one activist told Reuters by telephone.
In Egypt, demonstrators have been demanding prosecution of ousted leader Hosni Mubarak and accusing the generals who seized power after he resigned of shielding him from justice.
Protests were called off this week after authorities detained Mubarak and his two sons for questioning on accusations of abuse of power, embezzlement and the killing of protesters.
Mubarak was brought to hospital this week with what state media called a "heart crisis." The public prosecutor said on Friday he would be moved to a military hospital until he is well enough to face interrogation.
(Additional reporting by Mohamed Sudam in Sanaa, Asma Alsharif in Riyadh, Suleiman al-Khalidi in Amman and Marwa Awad in Sharm el-Sheikh; Writing by Peter Graff; editing by David Stamp)