AMMAN, Jordan — Syrian warplanes bombed a residential district of Aleppo on Sunday after rebels overran army barracks there, killing and wounding dozens of people and exacerbating a water shortage in Syria's biggest city after a pipeline burst, activists said.

Sunday's air raid destroyed a residential complex in the Hananu neighborhood, one of several in eastern Aleppo under rebel control, opposition activists told Reuters by phone.

The death toll was not immediately clear but dozens of bodies and wounded people were being dug out from the rubble. Video footage from the area showed scores of people searching and digging in the debris of a flattened building.

On-scene details could not be independently verified due to Syria's severe restrictions on international media access.

Aerial bombardment had also wrecked a main water pipeline, causing serious shortages of water in Aleppo, Syria's commercial and industrial capital, activists added.

"A water pumping station in al-Mayadeen was hit. There were rebels in the area, but this is not a justification to bomb civilian infrastructure," activist Ahmad Saeed said.

A businessman who went from the northwest of the city to Hananu to bury his grandmother -- Aleppo's main cemetery is in the district -- said the ground was shaking with artillery explosions.

"I passed by several [rebel] Free Syrian Army checkpoints. The fighters looked quite relaxed. The army was nowhere to be seen but it was bombing heavily," he said.

ATTACK ON REFUGEE CAMP

Syrian troops stormed into a Palestinian refugee district in Damascus, opposition activists said, after a four-day artillery assault on the southern suburb where rebels fighting to oust President Bashar al-Assad have dug in.

Assad's forces have preferred to use air power and artillery to hit areas where rebels are positioned and infantry raids normally occur only once many have fled. Activists said they feared for civilian inhabitants in the latest offensive.

On Sunday, the army continued to shell the Palestinian refugee camp of Yarmouk in south Damascus and the adjacent impoverished neighborhood of Hajar al-Aswad, home to thousands of refugees from the Israeli-occupied Golan Heights.

FIGHTING WIDENS

The almost 18-month-old conflict also spilled further over borders when three rockets fired from Syria crashed into an Iraqi frontier town, killing a 5-year-old girl, according to local inhabitants and Iraqi officials.

As rebels fought government forces for an airfield and military base near the Syrian border town of Albu Kamal, Katyusha rockets hit a residential area of al Qaim in Iraq, smashing through a wall of one house and killing the girl inside.

"She was sitting on my lap just before we heard the rocket. I knew she was dead immediately after the explosion," said Firas Attallah, the girl's father, showing a bloodstained mattress amid the shattered glass in his home.

Assad's use of military force to quell an uprising that began almost 18 months ago as a peaceful pro-democracy movement has cost him many allies in the Arab and Muslim world and caused a trickle of defections from Syrian government and army ranks.

And on Sunday, Syrian state media said four people were killed in a "terrorist attack" that targeted a bus in the province of Homs. The London-based Syrian Observatory for Human Rights said civilians and soldiers were in the bus.

Two Syrian diplomats in Malaysia announced late on Friday that they had joined the opposition, according to a report by pan-Arab television channel Al Arabiya.

Two men identifying themselves as First Secretary Imad Ahmar and Attaché Mahmoud Obedi from Syria's Kuala Lumpur embassy read a statement on the channel declaring their "support for the Syrian people's revolution against the tyrannical regime."

But the defections so far are seen largely as symbolic and Assad has increasingly relied on a close circle of relatives and senior members of his minority Alawite sect dominating the ruling elite to maintain his grip on power.

NEW SANCTIONS DISCUSSED

Anxious to end the bloodshed, European Union diplomats said on Saturday the 27-nation bloc might impose new sanctions on the Syrian government as soon as next month.

Speaking after visiting a Syrian refugee camp in Jordan, German Foreign Minister Guido Westerwelle said he saw "the first signs of erosion in the regime of Assad."

"It is necessary we isolate the regime of Bashar al-Assad," he told a news conference. "We will use the next weeks while Germany has the presidency of the [U.N.] Security Council to work on this isolation and to increase the pressure on this regime. We think he has gone too far and his time is over."

CAMP HOSPITAL STORMED

Syrian activist Abu Yasser al-Shami said that his friends living in Yarmouk, a densely populated Palestinian refugee camp where 10 people were killed Friday in shelling, had fled the area on Saturday morning after government troops swept in.

"Assad's forces stormed al-Basel hospital in Yarmouk Camp and arrested many of the injured civilians," he said over Skype.

When insurgents thrust into central parts of the capital in July, they were swiftly pushed back to southern districts, like Yarmouk, where there is a thinner state security presence.

But residents complain that the army uses indiscriminate artillery and air strikes. Palestinians have been divided over whether or not to support Assad, but there are signs that more and more are now starting to back the uprising.

The Syrian Observatory for Human Rights, an opposition watchdog group based in London, said shells rained down on Hajar al-Aswad district, which neighbors Yarmouk, on Saturday.

It said 170 people were killed in bloodshed on Friday across the country, many of them in Damascus and northern Aleppo, where rebels say they control more than half of what is Syria's most populous city and commercial center.

The Observatory says more than 23,000 people have died in an uprising that has lasted more than 17 months. About 200,000 Syrians have fled to neighboring Turkey, Jordan and Iraq.

The conflict is spilling over Syrian borders and has raised sectarian tensions in the region given that the revolt has been led by majority Sunni Muslims against a president who is Alawite, an offshoot of Shiite Islam.

ARREST IN SYRIA-RELATED KIDNAPPING

Lebanon's army forces raided a southern district of Beirut late on Friday and arrested a member of a powerful Shiite clan which has claimed responsibility for the kidnapping of 20 Syrians and a Turkish businessman.

The army arrested Hassan Meqdad, from the Meqdad clan, which abducted the men on Aug. 15 in what they said was a response to the capture of one of their kinsmen in Damascus by the rebel Free Syrian Army.

Damascus continues to exert influence over its smaller neighbor and had troops garrisoned in Lebanon until 2005.

The Meqdads are one of many armed groups in Lebanon which continue to exert power. The northern port city of Tripoli has seen sporadic clashes between Assad's supporters and his foes.

"The [army] continues its search for a number of culprits who fled to various Lebanese regions and plans to maintain its work for the release of all hostages," an army statement said. It added that large quantities of weapons and ammunition were seized during the raid on the Rweiss district of Beirut.

The United States has accused Russia and China of effectively prolonging Syria's bloodletting by blocking efforts at the U.N. Security Council to approve tough sanctions aimed at reining in the Assad government.

Russian Foreign Minister Sergei Lavrov said at a summit of Pacific rim states that Moscow and Western powers remained at loggerheads over how to defuse the conflict — a diplomatic impasse in which Western officials say violence has flourished.

"Our U.S. partners prefer measures like threats, increased pressure and new sanctions against both Syria and Iran. We do not agree with this in principle," Lavrov told reporters. Russia and Iran are Assad's closest allies.

Lavrov said Russia expected the Security Council later this month to formally endorse an agreement brokered by former U.N. Syria envoy Kofi Annan which envisages a transitional governing authority for Syria.

Washington has angered Russia by going outside the United Nations to work with allies on the Syrian opposition's behalf. But U.S. Secretary of State Hillary Clinton told Lavrov it was possible to return to the United Nations if Moscow and Beijing were ready to forego their vetoes and back stronger measures.