By Suleiman al-Khalidi and Simon Cameron-Moore
ISTANBUL (Reuters) - Syria's fractured opposition elected a National Salvation Council to present a united challenge to President Bashar al-Assad's rule as he intensified a military campaign to crush an uprising against his rule.
The opposition meeting in Istanbul took place Saturday, a day after the biggest demonstrations so far in Syria's four-month uprising, during which at least 32 civilians were killed, including 23 in the capital Damascus.
"We shall work toward reaching out toward other opposition groups to lead the country toward the democratic vision we have," prominent opposition figure Haitham al-Maleh told Reuters after the one-day meeting.
Despite disputes over whether to form a government-in-waiting or wait to see how the uprising unfolds, the meeting concluded with the election of a 25-member National Salvation council composed of Islamists, liberals and independents.
Of the close to 350 people who attended the opposition congress, many were Syrian exiles who had left the country years earlier.
The meeting had hoped to join members of the opposition inside Syria via a video link to a conference in Damascus, but that was called off after Syrian security forces targeted the venue as part of Friday's crackdown in the capital.
The Council will meet Sunday to appoint an 11-member committee, and a further meeting with be held in a bid to tighten bonds between the various opposition groups.
The West has criticised Assad's crackdown on four months of protests demanding political freedoms. Syrian forces killed one protester and wounded five Saturday when they opened fire at demonstrators in the eastern border town of Albu Kamal near Iraq's Sunni heartland.
The official state news agency said "armed terrorist groups" killed three security personnel Saturday in Albu Kamal, a poor town despite being surrounded by oil fields, where tens of thousands of people rallied Friday to demand Assad's removal.
Human rights campaigners said Syrian forces killed at least three other civilians in the rest of Syria Saturday when they fired at funerals for protesters killed the day before.
U.S. Secretary of State Hillary Clinton, visiting Turkey, said Assad's repression was "troubling."
"The brutality has to stop," she said in a televised interview with a group of young Turkish people at an Istanbul coffee shop Saturday.
At a joint news conference with Turkey's Foreign Minister Ahmet Davutoglu, Clinton said: "Now Syria's future is up to the Syrian people, but of course the efforts by the opposition to come together to organize and to articulate an agenda are an important part of political reform."
She expressed hope the people and Assad's government could be reconciled to work together.
"It's what the Syrian people are doing, trying to form an opposition that can provide a pathway hopefully in peaceful cooperation with government to a better future."
Davutoglu repeated warnings to Assad's government to implement reform or face being swept away by democratic forces.
"A government that does not consider the demands of its society won't survive," said Davutoglu, who had earlier urged Assad to undertake "shock therapy" reforms.
"Assad said he was going to have multi -party groups in parliament ... I hope Syria has opposition parties and that Syria has opposition parties that raise their voice," he said.
Human rights campaigners say more than 12,000 Syrians have been arbitrarily arrested during the uprising.
Witnesses said militiamen loyal to Assad attacked with sticks 28 actors and writers Saturday as they left the Palace of Justice in Damascus, where a judge freed them after their arrest this week for staging a demonstration demanding political freedoms.
Activists said discontent is growing within the mostly Sunni rank and file of the army as the crackdown orchestrated by Assad from Syria's minority Alawite sect continues.
They said around 100 Air Force Intelligence personnel and the crew of at least four armoured vehicles joined protesters' ranks in the eastern border town of Albu Kamal in the tribal Deir al-Zor province near Iraq's Sunni heartland following the killing by Military Intelligence agents of four protesters, including a 14 year old boy, Saturday.
"The whole of Albu Kamal went to the streets after the killings. Several armoured personnel carriers moved into the center of the town to stop them but ended joining sides with the human waves," one of the activists in the region, who did not want to be named for fear of reprisal by secret police, told Reuters by phone.
An exiled dissident at the Istanbul meeting called on Syrians to wage a campaign of civil disobedience to try to force Assad from power.
"I'm for anything that unifies the Syrian people and helps our people inside, and unifies our ranks in confronting this illegitimate repressive regime that has usurped power and human rights," opposition figure Wael al Hafez told the meeting, echoing comments made by others.
(Reporting by Suleiman al-Khalidi and Simon Cameron-Moore; Writing by Sophie Hares; Editing by Michael Roddy)