A Free Syrian Army fighter fires a RPG as a Syrian Army tank shell hits a building across a street during heavy fighting in the Salaheddine neighbourhood of central Aleppo, Aug 11, 2012. [Photo/Agencies]

Urban battles and violence continued Saturday in different parts across Syria at a time the UN Supervision Mission in Syria said it's deeply concerned about the ongoing violence and considering the situation as "volatile and unpredictable."

Syria's state-run SANA news agency said the authorities on Saturday pursued armed "terrorist" groups in a number of areas in northern Aleppo province, such as in al-Fayd, al-Jamiliyeh, al- Khaldiyeh and Kafr Hamra, killing several terrorists, including four Libyans who were heading to Aleppo city to support the armed groups, according to SANA.

Also in Aleppo, SANA said army unit repelled an armed " terrorist" group that attempted to attack the Radio and TV center in al-Iza'a neighborhood, inflicting heavy losses on the assailants, some of whom were killed or injured while the rest fled the area.

SANA said that another army unit confronted an armed group that attempted to attack Aleppo's Central Prison, killing and injuring many of the attackers. It is the third attempt by the armed groups targeting the Central Prison.

On a relevant note, Aleppo governorate and civil defense began to clean up the rubble and aftermath of the destruction caused by the clashes in Salahudien neighborhood in preparation for restoring the neighborhood's infrastructure and utilities, said SANA.

In Homs, the authorities clashed with armed groups driving two vehicles equipped with Dushka machineguns as the latter tried to attack the law-enforcement forces in al-Ghasaniyeh town in al- Qseir countryside.

SANA said the two cars were destroyed and the armed men inside were killed.

In the capital Damascus, an armed group detonated on Saturday an explosive device in al-Marjeh neighborhood near Victoria Bridge and shot randomly to terrify civilians, said SANA.

The explosion caused no injuries or damages, while the security forces pursued the assailants and arrested them.

The state news agency reported clashes also in the southern province of Daraa and eastern Deir al-Zour province.

Meanwhile, an armed group on Saturday evening assassinated journalist Ali Abbas, head of the Internal News Department at SANA, in his home in Jdaidet Artouz, Damascus countryside, SANA reported.

The assassination of Abbas is the latest in a series of attacks that have been targeting Journalists and staffers of Syria's official and pro-government media men.

On the opposition side, the Britain-based Syrian Observatory for Human Rights said the Aleppo neighborhoods of al-Sakhour, Bustan al-Qasr, Saif al-Dawla, al-Ansari, al-Amriya and Salahuddien were bombarded by government forces, adding that the Syrian forces used fighter jets in the assault.

It said several were injured and houses were destroyed, adding that a rebel fighter was killed in the al-Helk neighborhood, by the gunfire and bombardment that the neighborhood witnessed.

In the suburbs of Damascus, the Observatory said the towns and cities of al-Dumeir, Douma, Harasta, al-Zabadani, al-Tel, Saqba, Deir al-Asafeer, and Ghouta al-Sharkiya have been subject to violent bombardment by government forces.

The Local Coordination Committees, another activists' network, placed the death toll of Saturday's violence at 80. However, there has been no independent confirmation of activists' accounts.

While the violence rages on, Syria's newly appointed Prime Minister Wael Halki was sworn in on Saturday before the Syrian President Bashar al-Assad.

Assad appointed al-Halki on Thursday after sacking the former Prime Minister Riad Hijab, who defected his post last Sunday and sought asylum in Jordan.

Halki, a 48-year-old gynecologist, was appointed as head of the doctors' syndicate in 2010 and later served as health minister.

The defection of Hijab, despite attempts by the government to downplay its importance, is considered as a humiliating blow to the recently-formed government.

Meanwhile, spokesperson of the UN Supervision Mission in Syria told Xinhua that the observers are monitoring the levels of violence and the use of heavy weapons and its impact on civilians.

"The situation throughout the country remains volatile and unpredictable," the spokesperson said, adding that the mission is "extremely concerned about the price that Syrian civilians are paying due to the ongoing violence."