ABC News' Terry Moran and his team take a rare and dangerous journey into the embattled Syrian capital of Damascus for the special report : Inside Syria: The Battle for Damascus.

It's dark here now. Downtown Damascus seems shaken to its core by today's attacks.

At 11 a.m., at a crowded traffic circle near the city's heart, a car bombing left not only a crater but charred hulks of cars, a truck and a city bus in its wake. Blood and burnt corpses littered the street.

As ABC News arrived on the scene, where a school stood close by, a small body bag was loaded into an ambulance.

At a military hospital, where more than 70 of the wounded had been taken, a little boy was being treated for injuries sustained when debris ripped through him. His father, who was walking beside him when the blast occurred, sat on the end of the bed in tears.

A woman, her legs badly injured, wept because she'd been separated from her 4-month-old baby girl when the blast hit them and she did not know where her child was. Doctors said the mother would likely lose both her legs.

Image credit: SANA/AP Photo

A man with his head and face badly wounded and bandaged, cried out to God - and declared loyalty to Syrian President Bashar Assad.

An office building of the local Ba'ath Party - Assad's ruling party - was blown out by the blast and may have been its intended target.

At the hospital, a weary doctor who had been working all day said America was to blame.

He was polite, but firm. A father of four, he said every time he approached one of the children hurt, he thought of his kids.

We have heard that more than 50 are dead and more than 200 are injured. The death toll is likely to rise.

Syrian law enforcement says that a second suicide bomber was arrested in the area after the blast, perhaps preparing to detonate a follow-on attack as emergency workers and others responded to the initial carnage.

As ABC News has been reporting for some time, and as NGOs like the International Crisis Group have been documenting, the armed rebellion here is being rapidly radicalized.

Jihadists - including those who self-identify as al Qaeda - play an increasingly important role on the frontlines of the fighting and so are increasingly determining the character of the civil war.

The increasing pace of mortar attacks, a notoriously inaccurate weapon almost guaranteed to cause "collateral damage"; kidnappings, executions and IEDs; and today's massive blast suggest that the tactic of terror has become a weapon of choice on the Damascus battlefield.

And in fact it feels to Damascenes that the war is closing in on them, that their zone of safety is vanishing altogether and that terror will slowly choke life out of this diverse and tolerant city.

Finally, all day long, as if in anguished retaliation, the government's artillery positions on the hills above town have been firing away at the rebels in the suburbs.