The United Nations expressed grave concern about twin suicide car bombings in Damascus and condemned the attacks that killed 44 people and lent a grim new face to the uprising in Syria.
With world powers arguing about details of a U.N. resolution on Syria, U.N. Secretary-General Ban Ki-moon called for an immediate end to the bloodshed and urged the Syrian government to implement a peace plan proposed by the Arab League.
The first batch of 50 Arab League monitors will head to Syria on Monday to assess whether Damascus is abiding by an Arab peace plan, Egypt's state news agency reported on Friday.
European and U.S. officials want the U.N. Security Council to impose an arms embargo and other sanctions on Syria's government because of its nine-month-old crackdown on protesters against the rule of President Bashar al-Assad, which U.N. officials say has killed more than 5,000 people.
The suicide bombs, aimed at two security buildings, sent human limbs flying and streets in Syria's capital were littered with human remains and the blackened hulk of cars.
Foreign Ministry spokesman Jihad Makdesi said the attacks were carried out by terrorists (trying) to sabotage the will for change in Syria, and followed warnings from Lebanon that al Qaeda fighters had infiltrated Syria from Lebanese territory.
Some of Assad's opponents said the suicide attacks could have been staged by the government itself.
The U.N. Security Council condemned the terrorist attacks.
Terrorism in all its forms and manifestations constitutes one of the most serious threats to international peace and security, and ... any acts of terrorism are criminal and unjustifiable, its statement said.
Western powers say government security forces have been responsible for most of the violence in Syria. But Russia, an old ally of Damascus, wants any resolution to be even-handed.
If the requirement is that we drop all reference to violence coming from extreme opposition, that's not going to happen, U.N. ambassador Vitaly Churkin said in New York after Russia submitted a revised draft resolution to the council.
If they expect us to have arms embargo, that's not going to happen, he said. We know what arms embargo means these days. It means that - we saw it in Libya - that you cannot supply weapons to the government but everybody else can supply weapons to various opposition groups.
German Ambassador Peter Wittig said the latest Russian draft did not go far enough. We need to put the weight of the council behind the Arab League, he said.
That includes the demands to release political prisoners, that includes a clear signal for accountability for those who have perpetrated human rights violations.
Assad has used tanks and troops to try to crush the street protests inspired by other Arab uprisings this year. Such rallies are now increasingly eclipsed by an armed insurgency against his security apparatus.
But Friday's blasts signalled a dramatic escalation.
It's a new phase. We're getting militarised here, said Joshua Landis, a Syria expert at the University of Oklahoma who felt Friday's bombs were a small premonition of what may come in a country that some analysts see slipping towards civil war.
This is when the Syrian opposition is beginning to realise they are on their own, he added, referring to Western reluctance to intervene militarily in Syria.
The interior ministry spokesman said 166 people were wounded by the Damascus explosions. It broadcast footage of mangled bodies being carried in blankets and stretchers into ambulances, a row of corpses wrapped in sheets lying in the street.
The United States condemned the attacks, saying there was no justification for terrorism of any kind and that the work of the Arab League should not be hindered.
There was no immediate claim of responsibility. Al Qaeda are Sunni Muslim militants. Assad and Syria's power elite belong to the Alawite branch of Shi'ite Islam while the majority of Syrians, including protesters and insurgents, are Sunnis.
I'm defending my people, Ali, 45, an Alawite factory worker issued by police with a gun which he has used against protesters in the city of Homs, said in comments passed on to Reuters. We can't let them topple the regime, they'll go after us and kill us all.
Syria has generally barred foreign media from the country, making it hard to verify accounts of events from either side.
The opposition Syrian Observatory for Human Rights said 15 civilians were killed outside the capital on Friday, eight of them in Homs.
The Arab League peace plan stipulates a withdrawal of troops from protest-hit cities and towns, release of prisoners and dialogue with the opposition.
Damascus says more than 1,000 prisoners have been freed since the Arab plan was agreed and the army has pulled out of cities. Anti-Assad activists say no such pullout has occurred.
Syrian Oil Minister Sufian Alao said on Saturday that his country's oil production had fallen by about 30 to 35 percent as a result of sanctions imposed on Syria over its crackdown.
The European Union has stepped up its sanctions against Syria's oil industry, including blacklisting state-owned firms. The Arab League has also imposed sanctions on financial and other dealings with Syria.
(Additional reporting by Dominic Evans and Louis Charbonneau; Writing by Andrew Roche; Editing by Peter Millership)