AMMAN The Muslim Brotherhood called on Syrians to take to the streets on Friday and help the besieged city of Deraa, where a rights group said civilian deaths from a tank-backed army attack rose to 50.
It was the first time that the Brotherhood, ruthlessly crushed along with secular leftist movements under the rule of late President Hafez al-Assad, had called directly for protests in Syria since pro-democracy demonstrations against Assad's son, President Bashar al-Assad, erupted six weeks ago.
A declaration by the Brotherhood, sent to Reuters by its leadership in exile on Thursday, said: "Do not let the regime besiege your compatriots. Chant with one voice for freedom and dignity. Do not allow the tyrant to enslave you. God is great."
In Deraa itself, defiant residents said the army assault had failed to silence the southern city of 120,000 people.
"Despite everything people came out after evening prayers yesterday and were crying 'God is Greater' from rooftops. We want to resist them even if it's only with our voices," a man who identified himself only as Abu Zaid said by telephone.
"The villages around Deraa are all planning to flock to the city in solidarity despite the roadblocks and the siege around the city," said another resident called Jasem.
Witnesses said roads into Damascus were closed on Friday morning, to prevent people marching from the rural areas around the capital into the city.
Wissam Tarif, director of the Insan human rights organisation, said snipers were visible in several Damascus suburbs, including Harasta, Daraya, and Douma from where protesters had tried to march into the centre of the capital in the last two weeks, only to be met by bullets.
Another witness said Republican Guard trucks equipped with machine guns patrolled the circular road around Damascus.
The protests have drawn a cross section of Syrian society, which has been under Baath Party rule for the last 48 years. The younger Assad preserved the autocratic political system he inherited in 2000 while the family expanded its control over Syria's struggling economy.
The upheaval could have heavy regional repercussions since Syria straddles the fault lines of the Middle East conflict, maintaining an anti-Israel alliance with Iran and backing the Hezbollah and Hamas militant movements.
The Brotherhood said accusations by Syrian authorities that militant Islamists were behind the unrest were aimed at fomenting civil war and undermining nationwide demands for political freedoms and an end to corruption.
But a Jordanian Islamist, Abu Muhammad al-Maqdisi, said that Muslims were obliged to join the protest and that the overthrow of Assad's minority Alawite rule would be a step towards implementing Sharia law in the mainly Sunni Muslim state.
Maqdisi was a spiritual mentor of the late Jordanian-born militant Abu Musab al-Zarqawi, who led al Qaeda in Iraq.
Friday, the Muslim day of rest and prayers, has been the main opportunity for protesters to gather, challenging repeated warnings by the authorities not to demonstrate.
Security forces shot dead at least 120 protesters last Friday, said Syrian human rights organisation Sawasiah, in the biggest demonstrations Syria has seen since the democratic uprising ignited in Deraa on March 18, with pro-democracy rallies spreading to regions across the rest of the country.
Three days later the Fourth Mechanised Division, under the control of Assad brother's Maher, stormed Deraa.
That echoed their father's 1982 attack on the city of Hama to crush a revolt led by the Muslim Brotherhood, killing anywhere between 10,000 and 30,000 people.
Residents said there had been confrontations between different army units in Deraa on Monday, with some firing on their own side to let residents drag wounded from the street.
Al Jazeera television broadcast footage on Friday which appeared to show men in uniform marching alongside protesters, possibly in the Deraa region.
In another sign of rare dissent under Assad's monolithic rule, 200 members of the Baath Party resigned on Wednesday in protest at the violent suppression of demonstrators.
Assad tightened the security grip in and around Damascus on Thursday, with various security forces and secret police units deploying in nearby towns, Erbin and Tel, and in the Damascus district of Barzeh, rights activists and witnesses said.
The Syrian Observatory for Human Rights said the attack on Deraa has killed at least 50 civilians, with essential supplies in the city running law.
The offensive intensified criticism of Assad in the West, which had taken steps to rehabilitate the Syrian ruler in the last three years. The United States says it is considering tightening sanctions.
Ambassadors of European Union governments to Brussels planned to meet on Friday to discuss the possibility of imposing sanctions against Syria, which could include asset freezes and travel restrictions on key officials.
One EU diplomat said it may be too early for the bloc to make a binding decision on Friday but governments could send a message signalling sanctions were on the table.
"I'd expect a political signal towards sanctions but maybe not a decision yet," the diplomat said.
Other EU measures against Syria could include freezing financial aid, which amounts to 43 million euros ($64 million) a year.
(Additional reporting by Suleiman al-Khalidi in Amman; editing by Mark Heinrich)