BEIRUT - Battles raged through the night and into Thursday in several districts of Syria's second city Aleppo, a monitoring group said, as activists reported clashes in the Palestinian Yarmouk camp in Damascus.

The battles in Aleppo followed a day of heavy fighting there and came after Syria's regime rushed reinforcements to the northern city, where rebels on July 20 launched an all-out assault for control of the country's commercial hub.

"There are clashes in the Muhafaza district and shelling on the Mushhad and Sheikh Badr neighbourhoods, which killed a child and injured seven people," the Britain-based Syrian Observatory for Human Rights said.

Aleppo's Salaheddin neighbourhood, scene of fierce fighting for days, was also bombarded by regime troops during the night, the group said.

Despite the fighting, there were "mass demonstrations in the Furqan, Ashrafiyeh and New Aleppo districts calling for the fall of the regime and the departure of President Bashar al-Assad," the Observatory said.

The watchdog reported 19 civilians and three rebels killed in Aleppo fighting on Wednesday but did not give a separate toll of soldiers killed in the city.

Several rural villages and towns in the Aleppo province were being shelled by the Syrian army, it said.

In Damascus, street battles were being fought on Thursday in the Palestinian Yarmouk camp in the south of the capital, the Observatory said.

"There are clashes on Street 30 in the Yarmouk camp between Syrian regime forces and fighters from rebel units. Explosions can be heard," it said.

A resident of the camp reached by phone confirmed the fighting.

"It started at 7:00 am. The night was quiet. They are using RPGs and heavy machineguns," he said.

After a week of heavy clashes in Damascus, activists say regime forces have largely regained control of the city, with only a few pockets of continued fighting remaining.

The Observatory also reported fighting in Deir Ezzor in the east of Syria, where it said two people were killed overnight, including one shot by a sniper.

In an updated toll on Thursday, the Observatory said 143 people were killed throughout Syria on Wednesday, including 75 civilians, 41 soldiers and 27 rebel fighters.

More defections

The United States on Wednesday confirmed the defections of two more senior Syrian diplomats, describing this as further evidence that President Bashar al-Assad's days are "numbered."

"We can confirm the defections of Syrian ambassadors to both the UAE and Cyprus," White House spokesman Jay Carney told reporters aboard Air Force One. Earlier, sources had said the two envoys had defected from the regime.

Carney said the move showed that "senior officials around the Assad inner circle are fleeing the government because of the heinous actions taken by Assad against his own people, and the recognition that Assad's days are numbered."

Earlier, a high-level source said on condition of anonymity that Syria's charge d'affaires in Cyprus, Lamia Hariri, has defected from the regime.

An opposition activist in the country confirmed that Hariri's husband, Syria's ambassador to the United Arab Emirates, Abdel Latif al-Dabbagh, had also defected.

Qatar-based Al-Jazeera television said on Wednesday that Dabbagh had defected, though it did not say where he was.

But a senior State Department official confirmed to AFP that "Dabbagh has defected to Qatar and has joined the growing number of Syrians who are doing what is right for the Syrian people."

"These defections serve as a reminder that the bottom is starting to fall out of the regime. It is crumbling and losing its grip on power," the official added, asking to remain anonymous.

The string of defections come after Nawaf Fares, Syria's ambassador to Iraq, left for Qatar this month after publicly renouncing his post.