Missile strike in northern Syria kills 33

Many were trapped under the rubble of destroyed houses and piles of concrete and the death toll could still rise further if more bodies are uncovered.

The apparent ground-to-ground missile attack struck a quiet area that has been held by anti-regime fighters for many months, a reminder of how difficult it is for the opposition to defend territory in the face of the regime's far superior weaponry.

In the capital Damascus, state-run news agency SANA said two mortars exploded near one of President Bashar Assad's palaces. It dealt a symbolic blow to the embattled leader, who has tried to maintain an image as the head of a functioning state even as rebels edge closer to the heart of his seat of power.

No casualties were reported and it was unclear whether Assad was in the palace. He has two others in the city.

The attack was the first confirmed strike close to a presidential palace and another sign that the civil war is seeping into areas of the capital once considered safe.

"This is a clear message to the regime that nowhere is safe from now on," said Khaled al-Shami, an activist in Damascus reached via Skype. "The fact that they had to announce it means they can no longer hide what is happening in Damascus."

The news service, SANA, said "terrorists" fired the rounds that struck near the southern wall of the Tishreen palace in the capital's northwestern Muhajireen district. The government refers to anti-government fighters as "terrorists."

Assad often uses the Tishrin palace to receive dignitaries and as a guest house for foreign officials during their visits to Syria.

The capital has largely been spared the violence that has left other cities in ruins. For weeks, however, rebels who have established footholds in the suburbs have been pushing closer to the heart of Damascus from the eastern and southern outskirts, clashing with government forces.

Rebels have claimed to fire rockets at presidential palaces in Damascus before, but this strike was the first confirmed by the government.

In the northern city of Aleppo, anti-regime activists said a missile strike flattened a stretch of buildings and killed at least 33 people. The Britain-based Syrian Observatory for Human Rights said they included 14 children and five women.

Amateur videos posted online showed scores of men combing through the rubble of destroyed buildings in the poor Jabal Badro neighborhood to find those trapped beneath it.

"Allahu Akbar," or God is great, they shout as a group of men lift up a body wrapped in a pink blanket.

One man swung a sledgehammer to break through concrete while a bulldozer hauled off rubble. In another video, a man covered in grey dust struggled under pile of concrete.

The videos appeared authentic and corresponded with other Associated Press reporting.

The Jabal Badro district has been under rebel control for months and had been largely quiet until Tuesday's attack.

The strike was the latest salvo in a fierce and bloody 7-month battle for Syria's largest city and economic center, a key prize in the civil war.

Rebels have slowly expanded their control over parts of Aleppo since first storming it last summer. The city is now divided between rebel- and regime-controlled zones.

Rebel forces have been trying for weeks to capture Aleppo's international airport and two military air bases nearby, while the government is bringing in reinforcements from areas it still controls further south and regularly bombing rebel areas from the air.